31077840 has 40 divisors (see below), whose sum is σ = 96342048. Its totient is φ = 8287360.

The previous prime is 31077811. The next prime is 31077847. The reversal of 31077840 is 4877013.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 31077798 and 31077807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31077847) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 64506 + ... + 64985.

Almost surely, 2^31077840 is an apocalyptic number.

31077840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31077840 is an abundant number, since it is smaller than the sum of its proper divisors (65264208).

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

31077840 is a wasteful number, since it uses less digits than its factorization.

31077840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129507 (or 129501 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 31077840 is about 5574.7502186197. The cubic root of 31077840 is about 314.4007756587.

The spelling of 31077840 in words is "thirty-one million, seventy-seven thousand, eight hundred forty".