31004640 has 96 divisors (see below), whose sum is σ = 108531360. Its totient is φ = 8266752.

The previous prime is 31004593. The next prime is 31004669. The reversal of 31004640 is 4640013.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×31004640² = 1922575403059200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 732 + ... + 7908.

It is an arithmetic number, because the mean of its divisors is an integer number (1130535).

Almost surely, 2^31004640 is an apocalyptic number.

31004640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31004640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54265680).

31004640 is an abundant number, since it is smaller than the sum of its proper divisors (77526720).

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

31004640 is a wasteful number, since it uses less digits than its factorization.

31004640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7201 (or 7187 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 31004640 is about 5568.1810315398. The cubic root of 31004640 is about 314.1537375822.

Adding to 31004640 its reverse (4640013), we get a palindrome (35644653).

The spelling of 31004640 in words is "thirty-one million, four thousand, six hundred forty".