6491607621 has 16 divisors (see below), whose sum is σ = 9113264640. Its totient is φ = 4098956400.

The previous prime is 6491607611. The next prime is 6491607649. The reversal of 6491607621 is 1267061946.

It is not a de Polignac number, because 6491607621 - 2¹¹ = 6491605573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6491607611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270706 + ... + 293708.

It is an arithmetic number, because the mean of its divisors is an integer number (569579040).

Almost surely, 2^6491607621 is an apocalyptic number.

It is an amenable number.

6491607621 is a deficient number, since it is larger than the sum of its proper divisors (2621657019).

6491607621 is a wasteful number, since it uses less digits than its factorization.

6491607621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27976.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 6491607621 is about 80570.5133470056. The cubic root of 6491607621 is about 1865.4520363732.

The spelling of 6491607621 in words is "six billion, four hundred ninety-one million, six hundred seven thousand, six hundred twenty-one".