31749637920 has 1536 divisors, whose sum is σ = 149239480320. Its totient is φ = 5482414080.

The previous prime is 31749637919. The next prime is 31749637949. The reversal of 31749637920 is 2973694713.

It is a super-2 number, since 2×31749637920² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 1380419029 + ... + 1380419051.

It is an arithmetic number, because the mean of its divisors is an integer number (97161120).

Almost surely, 2^31749637920 is an apocalyptic number.

31749637920 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 31749637920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74619740160).

31749637920 is an abundant number, since it is smaller than the sum of its proper divisors (117489842400).

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

31749637920 is a wasteful number, since it uses less digits than its factorization.

31749637920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 1714608, while the sum is 51.

The spelling of 31749637920 in words is "thirty-one billion, seven hundred forty-nine million, six hundred thirty-seven thousand, nine hundred twenty".