72021131 has 12 divisors (see below), whose sum is σ = 90225072. Its totient is φ = 56983248.

The previous prime is 72021127. The next prime is 72021139. The reversal of 72021131 is 13112027.

It is not a de Polignac number, because 72021131 - 2² = 72021127 is a prime.

It is a super-2 number, since 2×72021131² = 10374086621038322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72021139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55895 + ... + 57168.

It is an arithmetic number, because the mean of its divisors is an integer number (7518756).

Almost surely, 2^72021131 is an apocalyptic number.

72021131 is a deficient number, since it is larger than the sum of its proper divisors (18203941).

72021131 is a wasteful number, since it uses less digits than its factorization.

72021131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113090 (or 113083 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 72021131 is about 8486.5264390091. The cubic root of 72021131 is about 416.0574590104.

Adding to 72021131 its reverse (13112027), we get a palindrome (85133158).

The spelling of 72021131 in words is "seventy-two million, twenty-one thousand, one hundred thirty-one".