1220472661 has 4 divisors (see below), whose sum is σ = 1222899552. Its totient is φ = 1218045772.

The previous prime is 1220472629. The next prime is 1220472703. The reversal of 1220472661 is 1662740221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1220472661 - 2⁵ = 1220472629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220472601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1212691 + ... + 1213696.

It is an arithmetic number, because the mean of its divisors is an integer number (305724888).

Almost surely, 2^1220472661 is an apocalyptic number.

It is an amenable number.

1220472661 is a deficient number, since it is larger than the sum of its proper divisors (2426891).

1220472661 is an equidigital number, since it uses as much as digits as its factorization.

1220472661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2426890.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 1220472661 is about 34935.2638604605. The cubic root of 1220472661 is about 1068.6677047721.

The spelling of 1220472661 in words is "one billion, two hundred twenty million, four hundred seventy-two thousand, six hundred sixty-one".