31486721247 has 32 divisors (see below), whose sum is σ = 47215311360. Its totient is φ = 20736959040.

The previous prime is 31486721239. The next prime is 31486721249. The reversal of 31486721247 is 74212768413.

31486721247 is a `hidden beast` number, since 314 + 86 + 7 + 212 + 47 = 666.

It is not a de Polignac number, because 31486721247 - 2³ = 31486721239 is a prime.

It is a super-2 number, since 2×31486721247² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31486721249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 713547 + ... + 756387.

It is an arithmetic number, because the mean of its divisors is an integer number (1475478480).

Almost surely, 2^31486721247 is an apocalyptic number.

31486721247 is a deficient number, since it is larger than the sum of its proper divisors (15728590113).

31486721247 is a wasteful number, since it uses less digits than its factorization.

31486721247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43180 (or 43174 counting only the distinct ones).

The product of its digits is 451584, while the sum is 45.

The spelling of 31486721247 in words is "thirty-one billion, four hundred eighty-six million, seven hundred twenty-one thousand, two hundred forty-seven".