1221174820 has 12 divisors (see below), whose sum is σ = 2564467164. Its totient is φ = 488469920.

The previous prime is 1221174809. The next prime is 1221174827. The reversal of 1221174820 is 284711221.

It can be written as a sum of positive squares in 2 ways, for example, as 216031204 + 1005143616 = 14698^2 + 31704^2 .

It is not an unprimeable number, because it can be changed into a prime (1221174827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30529351 + ... + 30529390.

It is an arithmetic number, because the mean of its divisors is an integer number (213705597).

Almost surely, 2^1221174820 is an apocalyptic number.

1221174820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221174820 is an abundant number, since it is smaller than the sum of its proper divisors (1343292344).

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

1221174820 is a wasteful number, since it uses less digits than its factorization.

1221174820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61058750 (or 61058748 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 1221174820 is about 34945.3118457970. The cubic root of 1221174820 is about 1068.8726064783.

The spelling of 1221174820 in words is "one billion, two hundred twenty-one million, one hundred seventy-four thousand, eight hundred twenty".