31423509 has 24 divisors (see below), whose sum is σ = 49070112. Its totient is φ = 19262880.

The previous prime is 31423499. The next prime is 31423517. The reversal of 31423509 is 90532413.

It is not a de Polignac number, because 31423509 - 2⁸ = 31423253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31423529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57174 + ... + 57720.

It is an arithmetic number, because the mean of its divisors is an integer number (2044588).

Almost surely, 2^31423509 is an apocalyptic number.

31423509 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

It is an amenable number.

31423509 is a deficient number, since it is larger than the sum of its proper divisors (17646603).

31423509 is a wasteful number, since it uses less digits than its factorization.

31423509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1057 (or 1054 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 31423509 is about 5605.6675784424. The cubic root of 31423509 is about 315.5621405910.

The spelling of 31423509 in words is "thirty-one million, four hundred twenty-three thousand, five hundred nine".