31214640 has 80 divisors (see below), whose sum is σ = 97993728. Its totient is φ = 8218368.

The previous prime is 31214639. The next prime is 31214641. The reversal of 31214640 is 4641213.

It is an interprime number because it is at equal distance from previous prime (31214639) and next prime (31214641).

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31214641) 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 15 ways as a sum of consecutive naturals, for example, 19137 + ... + 20703.

Almost surely, 2^31214640 is an apocalyptic number.

31214640 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 31214640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48996864).

31214640 is an abundant number, since it is smaller than the sum of its proper divisors (66779088).

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

31214640 is a wasteful number, since it uses less digits than its factorization.

31214640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666 (or 1660 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 31214640 is about 5587.0063540325. The cubic root of 31214640 is about 314.8614154810.

Adding to 31214640 its reverse (4641213), we get a palindrome (35855853).

The spelling of 31214640 in words is "thirty-one million, two hundred fourteen thousand, six hundred forty".