9721077640 has 16 divisors (see below), whose sum is σ = 21872424780. Its totient is φ = 3888431040.

The previous prime is 9721077623. The next prime is 9721077647. The reversal of 9721077640 is 467701279.

It can be written as a sum of positive squares in 2 ways, for example, as 9415597156 + 305480484 = 97034^2 + 17478^2 .

It is not an unprimeable number, because it can be changed into a prime (9721077647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121513431 + ... + 121513510.

Almost surely, 2^9721077640 is an apocalyptic number.

It is an amenable number.

9721077640 is an abundant number, since it is smaller than the sum of its proper divisors (12151347140).

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

9721077640 is a wasteful number, since it uses less digits than its factorization.

9721077640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243026952 (or 243026948 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 43.

The square root of 9721077640 is about 98595.5254562802. The cubic root of 9721077640 is about 2134.2148491314.

The spelling of 9721077640 in words is "nine billion, seven hundred twenty-one million, seventy-seven thousand, six hundred forty".