31415987 has 4 divisors (see below), whose sum is σ = 33069480. Its totient is φ = 29762496.

The previous prime is 31415981. The next prime is 31416013. The reversal of 31415987 is 78951413.

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 31415987 - 2⁴ = 31415971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31415987.

It is not an unprimeable number, because it can be changed into a prime (31415981) 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, 826718 + ... + 826755.

It is an arithmetic number, because the mean of its divisors is an integer number (8267370).

Almost surely, 2^31415987 is an apocalyptic number.

31415987 is a deficient number, since it is larger than the sum of its proper divisors (1653493).

31415987 is a wasteful number, since it uses less digits than its factorization.

31415987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653492.

The product of its digits is 30240, while the sum is 38.

The square root of 31415987 is about 5604.9966101685. The cubic root of 31415987 is about 315.5369593608.

Adding to 31415987 its sum of digits (38), we get a square (31416025 = 5605²).

The spelling of 31415987 in words is "thirty-one million, four hundred fifteen thousand, nine hundred eighty-seven".