1656664761 has 8 divisors (see below), whose sum is σ = 2210037984. Its totient is φ = 1103867360.

The previous prime is 1656664733. The next prime is 1656664783. The reversal of 1656664761 is 1674666561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1656664761 - 2⁵ = 1656664729 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1656664761.

It is not an unprimeable number, because it can be changed into a prime (1656664561) 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, 137196 + ... + 148781.

It is an arithmetic number, because the mean of its divisors is an integer number (276254748).

Almost surely, 2^1656664761 is an apocalyptic number.

It is an amenable number.

1656664761 is a deficient number, since it is larger than the sum of its proper divisors (553373223).

1656664761 is a wasteful number, since it uses less digits than its factorization.

1656664761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287911.

The product of its digits is 1088640, while the sum is 48.

The square root of 1656664761 is about 40702.1468844089. The cubic root of 1656664761 is about 1183.2546271970.

The spelling of 1656664761 in words is "one billion, six hundred fifty-six million, six hundred sixty-four thousand, seven hundred sixty-one".