1220656764 has 24 divisors (see below), whose sum is σ = 2882517120. Its totient is φ = 401983024.

The previous prime is 1220656757. The next prime is 1220656769. The reversal of 1220656764 is 4676560221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220656769) 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, 611784 + ... + 613775.

It is an arithmetic number, because the mean of its divisors is an integer number (120104880).

Almost surely, 2^1220656764 is an apocalyptic number.

It is an amenable number.

1220656764 is an abundant number, since it is smaller than the sum of its proper divisors (1661860356).

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

1220656764 is a wasteful number, since it uses less digits than its factorization.

1220656764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1225649 (or 1225647 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 39.

The square root of 1220656764 is about 34937.8986775106. The cubic root of 1220656764 is about 1068.7214366977.

The spelling of 1220656764 in words is "one billion, two hundred twenty million, six hundred fifty-six thousand, seven hundred sixty-four".