8147531621 has 4 divisors (see below), whose sum is σ = 8147822592. Its totient is φ = 8147240652.

The previous prime is 8147531617. The next prime is 8147531653. The reversal of 8147531621 is 1261357418.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1261357418 = 2 ⋅630678709.

It is a cyclic number.

It is not a de Polignac number, because 8147531621 - 2² = 8147531617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8147531671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98405 + ... + 161178.

It is an arithmetic number, because the mean of its divisors is an integer number (2036955648).

Almost surely, 2^8147531621 is an apocalyptic number.

It is an amenable number.

8147531621 is a deficient number, since it is larger than the sum of its proper divisors (290971).

8147531621 is a wasteful number, since it uses less digits than its factorization.

8147531621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290970.

The product of its digits is 40320, while the sum is 38.

The square root of 8147531621 is about 90263.6783041773. The cubic root of 8147531621 is about 2012.2194917140.

The spelling of 8147531621 in words is "eight billion, one hundred forty-seven million, five hundred thirty-one thousand, six hundred twenty-one".