7661044921 has 4 divisors (see below), whose sum is σ = 7790893200. Its totient is φ = 7531196644.

The previous prime is 7661044913. The next prime is 7661044939. The reversal of 7661044921 is 1294401667.

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 7661044921 - 2³ = 7661044913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7661044121) 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, 64924051 + ... + 64924168.

It is an arithmetic number, because the mean of its divisors is an integer number (1947723300).

Almost surely, 2^7661044921 is an apocalyptic number.

It is an amenable number.

7661044921 is a deficient number, since it is larger than the sum of its proper divisors (129848279).

7661044921 is a wasteful number, since it uses less digits than its factorization.

7661044921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129848278.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 7661044921 is about 87527.3952599985. The cubic root of 7661044921 is about 1971.3451540261.

The spelling of 7661044921 in words is "seven billion, six hundred sixty-one million, forty-four thousand, nine hundred twenty-one".