71998931 has 4 divisors (see below), whose sum is σ = 72866472. Its totient is φ = 71131392.

The previous prime is 71998921. The next prime is 71998933. The reversal of 71998931 is 13989917.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71998931 - 2⁶ = 71998867 is a prime.

It is a super-2 number, since 2×71998931² = 10367692130285522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71998933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 433646 + ... + 433811.

It is an arithmetic number, because the mean of its divisors is an integer number (18216618).

Almost surely, 2^71998931 is an apocalyptic number.

71998931 is a deficient number, since it is larger than the sum of its proper divisors (867541).

71998931 is an equidigital number, since it uses as much as digits as its factorization.

71998931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867540.

The product of its digits is 122472, while the sum is 47.

The square root of 71998931 is about 8485.2183825757. The cubic root of 71998931 is about 416.0147057024.

The spelling of 71998931 in words is "seventy-one million, nine hundred ninety-eight thousand, nine hundred thirty-one".