31689504 has 144 divisors (see below), whose sum is σ = 112432320. Its totient is φ = 8225280.

The previous prime is 31689499. The next prime is 31689509. The reversal of 31689504 is 40598613.

It is an interprime number because it is at equal distance from previous prime (31689499) and next prime (31689509).

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

31689504 is a modest number, since divided by 9504 gives 3168 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31689509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21462 + ... + 22890.

It is an arithmetic number, because the mean of its divisors is an integer number (780780).

Almost surely, 2^31689504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31689504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56216160).

31689504 is an abundant number, since it is smaller than the sum of its proper divisors (80742816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31689504 is a wasteful number, since it uses less digits than its factorization.

31689504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1463 (or 1452 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 31689504 is about 5629.3431233138. The cubic root of 31689504 is about 316.4500344145.

The spelling of 31689504 in words is "thirty-one million, six hundred eighty-nine thousand, five hundred four".