31361940 has 144 divisors (see below), whose sum is σ = 103822992. Its totient is φ = 7630848.

The previous prime is 31361933. The next prime is 31361947. The reversal of 31361940 is 4916313.

31361940 is a `hidden beast` number, since 3 + 1 + 3 + 619 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (31361933) and next prime (31361947).

It can be written as a sum of positive squares in 8 ways, for example, as 492804 + 30869136 = 702^2 + 5556^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31361947) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 113082 + ... + 113358.

It is an arithmetic number, because the mean of its divisors is an integer number (720993).

Almost surely, 2^31361940 is an apocalyptic number.

31361940 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 31361940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51911496).

31361940 is an abundant number, since it is smaller than the sum of its proper divisors (72461052).

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

31361940 is a wasteful number, since it uses less digits than its factorization.

31361940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 31361940 is about 5600.1732116069. The cubic root of 31361940 is about 315.3559091309.

The spelling of 31361940 in words is "thirty-one million, three hundred sixty-one thousand, nine hundred forty".