31139550 has 72 divisors (see below), whose sum is σ = 90114024. Its totient is φ = 7663680.

The previous prime is 31139543. The next prime is 31139557. The reversal of 31139550 is 5593113.

It is an interprime number because it is at equal distance from previous prime (31139543) and next prime (31139557).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31139557) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3189 + ... + 8511.

Almost surely, 2^31139550 is an apocalyptic number.

31139550 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31139550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45057012).

31139550 is an abundant number, since it is smaller than the sum of its proper divisors (58974474).

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

31139550 is a wasteful number, since it uses less digits than its factorization.

31139550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5354 (or 5346 counting only the distinct ones).

The product of its (nonzero) digits is 2025, while the sum is 27.

The square root of 31139550 is about 5580.2822509260. The cubic root of 31139550 is about 314.6087356747.

The spelling of 31139550 in words is "thirty-one million, one hundred thirty-nine thousand, five hundred fifty".