1227645820 has 24 divisors (see below), whose sum is σ = 2729707344. Its totient is φ = 462172416.

The previous prime is 1227645817. The next prime is 1227645823. The reversal of 1227645820 is 285467221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1227645817) and next prime (1227645823).

It is a super-2 number, since 2×1227645820² = 3014228518726944800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1227645820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1227645823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1805022 + ... + 1805701.

It is an arithmetic number, because the mean of its divisors is an integer number (113737806).

Almost surely, 2^1227645820 is an apocalyptic number.

1227645820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1227645820 is an abundant number, since it is smaller than the sum of its proper divisors (1502061524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1227645820 is a wasteful number, since it uses less digits than its factorization.

1227645820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3610749 (or 3610747 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 1227645820 is about 35037.7770413592. Note that the first 3 decimals coincide. The cubic root of 1227645820 is about 1070.7572652020.

The spelling of 1227645820 in words is "one billion, two hundred twenty-seven million, six hundred forty-five thousand, eight hundred twenty".