1220155651 has 32 divisors (see below), whose sum is σ = 1458003456. Its totient is φ = 1014948000.

The previous prime is 1220155639. The next prime is 1220155663. The reversal of 1220155651 is 1565510221.

It is an interprime number because it is at equal distance from previous prime (1220155639) and next prime (1220155663).

It is not a de Polignac number, because 1220155651 - 2⁷ = 1220155523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1220155051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2612520 + ... + 2612986.

It is an arithmetic number, because the mean of its divisors is an integer number (45562608).

Almost surely, 2^1220155651 is an apocalyptic number.

1220155651 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1220155651 is a deficient number, since it is larger than the sum of its proper divisors (237847805).

1220155651 is a wasteful number, since it uses less digits than its factorization.

1220155651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 28.

The square root of 1220155651 is about 34930.7264596659. The cubic root of 1220155651 is about 1068.5751702168.

Adding to 1220155651 its reverse (1565510221), we get a palindrome (2785665872).

The spelling of 1220155651 in words is "one billion, two hundred twenty million, one hundred fifty-five thousand, six hundred fifty-one".