8500721961 has 32 divisors (see below), whose sum is σ = 12475008000. Its totient is φ = 5124955968.

The previous prime is 8500721927. The next prime is 8500721963. The reversal of 8500721961 is 1691270058.

It is not a de Polignac number, because 8500721961 - 2²⁷ = 8366504233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8500721963) 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, 660930 + ... + 673668.

It is an arithmetic number, because the mean of its divisors is an integer number (389844000).

Almost surely, 2^8500721961 is an apocalyptic number.

It is an amenable number.

8500721961 is a deficient number, since it is larger than the sum of its proper divisors (3974286039).

8500721961 is a wasteful number, since it uses less digits than its factorization.

8500721961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13293.

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 8500721961 is about 92199.3598730490. The cubic root of 8500721961 is about 2040.8853296326.

The spelling of 8500721961 in words is "eight billion, five hundred million, seven hundred twenty-one thousand, nine hundred sixty-one".