1521791631 has 24 divisors (see below), whose sum is σ = 2289181440. Its totient is φ = 1010244312.

The previous prime is 1521791603. The next prime is 1521791633. The reversal of 1521791631 is 1361971251.

It is a happy number.

1521791631 is a `hidden beast` number, since 1 + 5 + 2 + 17 + 9 + 1 + 631 = 666.

It is not a de Polignac number, because 1521791631 - 2¹⁷ = 1521660559 is a prime.

It is a super-2 number, since 2×1521791631² = 4631699536363280322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521791633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44976 + ... + 71178.

It is an arithmetic number, because the mean of its divisors is an integer number (95382560).

Almost surely, 2^1521791631 is an apocalyptic number.

1521791631 is a deficient number, since it is larger than the sum of its proper divisors (767389809).

1521791631 is an equidigital number, since it uses as much as digits as its factorization.

1521791631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26457 (or 26445 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 1521791631 is about 39010.1477951571. The cubic root of 1521791631 is about 1150.2309885093.

The spelling of 1521791631 in words is "one billion, five hundred twenty-one million, seven hundred ninety-one thousand, six hundred thirty-one".