31161040 has 20 divisors (see below), whose sum is σ = 72449604. Its totient is φ = 12464384.

The previous prime is 31161019. The next prime is 31161041. The reversal of 31161040 is 4016113.

It can be written as a sum of positive squares in 2 ways, for example, as 14807104 + 16353936 = 3848^2 + 4044^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31161041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194677 + ... + 194836.

Almost surely, 2^31161040 is an apocalyptic number.

It is an amenable number.

31161040 is an abundant number, since it is smaller than the sum of its proper divisors (41288564).

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

31161040 is a wasteful number, since it uses less digits than its factorization.

31161040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389526 (or 389520 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 31161040 is about 5582.2074486712. The cubic root of 31161040 is about 314.6810915376.

Adding to 31161040 its reverse (4016113), we get a palindrome (35177153).

The spelling of 31161040 in words is "thirty-one million, one hundred sixty-one thousand, forty".