915631 has 2 divisors, whose sum is σ = 915632. Its totient is φ = 915630.

The previous prime is 915623. The next prime is 915641. The reversal of 915631 is 136519.

It is a weak prime.

It is an emirp because it is prime and its reverse (136519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 915631 - 2³ = 915623 is a prime.

It is a super-2 number, since 2×915631² = 1676760256322, which contains 22 as substring.

915631 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 915596 and 915605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (915601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 457815 + 457816.

It is an arithmetic number, because the mean of its divisors is an integer number (457816).

2⁹¹⁵⁶³¹ is an apocalyptic number.

915631 is a deficient number, since it is larger than the sum of its proper divisors (1).

915631 is an equidigital number, since it uses as much as digits as its factorization.

915631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 810, while the sum is 25.

The square root of 915631 is about 956.8860956248. The cubic root of 915631 is about 97.1046802737.

The spelling of 915631 in words is "nine hundred fifteen thousand, six hundred thirty-one".