31138380 has 144 divisors (see below), whose sum is σ = 116311104. Its totient is φ = 6566400.

The previous prime is 31138313. The next prime is 31138381. The reversal of 31138380 is 8383113.

It is a super-3 number, since 3×31138380³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31138381) 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, 15430 + ... + 17330.

It is an arithmetic number, because the mean of its divisors is an integer number (807716).

Almost surely, 2^31138380 is an apocalyptic number.

31138380 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 31138380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58155552).

31138380 is an abundant number, since it is smaller than the sum of its proper divisors (85172724).

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

31138380 is a wasteful number, since it uses less digits than its factorization.

31138380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936 (or 1931 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 31138380 is about 5580.1774165344. The cubic root of 31138380 is about 314.6047953819.

The spelling of 31138380 in words is "thirty-one million, one hundred thirty-eight thousand, three hundred eighty".