1531978368 has 64 divisors (see below), whose sum is σ = 4095397920. Its totient is φ = 507386880.

The previous prime is 1531978363. The next prime is 1531978369. The reversal of 1531978368 is 8638791351.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 1531978368.

It is not an unprimeable number, because it can be changed into a prime (1531978361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47583 + ... + 72993.

Almost surely, 2^1531978368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1531978368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2047698960).

1531978368 is an abundant number, since it is smaller than the sum of its proper divisors (2563419552).

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

1531978368 is a wasteful number, since it uses less digits than its factorization.

1531978368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25585 (or 25573 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 51.

The square root of 1531978368 is about 39140.4952446951. The cubic root of 1531978368 is about 1152.7917974747.

The spelling of 1531978368 in words is "one billion, five hundred thirty-one million, nine hundred seventy-eight thousand, three hundred sixty-eight".