71621931 has 16 divisors (see below), whose sum is σ = 99843840. Its totient is φ = 45582240.

The previous prime is 71621917. The next prime is 71621939. The reversal of 71621931 is 13912617.

It is not a de Polignac number, because 71621931 - 2⁹ = 71621419 is a prime.

It is a super-2 number, since 2×71621931² = 10259402000337522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71621939) 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 15 ways as a sum of consecutive naturals, for example, 66465 + ... + 67533.

It is an arithmetic number, because the mean of its divisors is an integer number (6240240).

Almost surely, 2^71621931 is an apocalyptic number.

71621931 is a deficient number, since it is larger than the sum of its proper divisors (28221909).

71621931 is a wasteful number, since it uses less digits than its factorization.

71621931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2066.

The product of its digits is 2268, while the sum is 30.

The square root of 71621931 is about 8462.9741226120. The cubic root of 71621931 is about 415.2873241305.

The spelling of 71621931 in words is "seventy-one million, six hundred twenty-one thousand, nine hundred thirty-one".