1220721612 has 48 divisors (see below), whose sum is σ = 3191284992. Its totient is φ = 359916480.

The previous prime is 1220721611. The next prime is 1220721613. The reversal of 1220721612 is 2161270221.

It is an interprime number because it is at equal distance from previous prime (1220721611) and next prime (1220721613).

It is a super-2 number, since 2×1220721612² = 2980322508007757088, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1220721611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120088 + ... + 129855.

It is an arithmetic number, because the mean of its divisors is an integer number (66485104).

Almost surely, 2^1220721612 is an apocalyptic number.

1220721612 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1220721612 is an abundant number, since it is smaller than the sum of its proper divisors (1970563380).

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

1220721612 is a wasteful number, since it uses less digits than its factorization.

1220721612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249998 (or 249996 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 1220721612 is about 34938.8267118402. The cubic root of 1220721612 is about 1068.7403618159.

Adding to 1220721612 its reverse (2161270221), we get a palindrome (3381991833).

The spelling of 1220721612 in words is "one billion, two hundred twenty million, seven hundred twenty-one thousand, six hundred twelve".