139521864 has 128 divisors (see below), whose sum is σ = 391910400. Its totient is φ = 41184000.

The previous prime is 139521847. The next prime is 139521869. The reversal of 139521864 is 468125931.

It is not an unprimeable number, because it can be changed into a prime (139521869) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 555739 + ... + 555989.

It is an arithmetic number, because the mean of its divisors is an integer number (3061800).

Almost surely, 2^139521864 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 139521864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195955200).

139521864 is an abundant number, since it is smaller than the sum of its proper divisors (252388536).

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

139521864 is a wasteful number, since it uses less digits than its factorization.

139521864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 351 counting only the distinct ones).

The product of its digits is 51840, while the sum is 39.

The square root of 139521864 is about 11811.9373516794. The cubic root of 139521864 is about 518.6576125402.

The spelling of 139521864 in words is "one hundred thirty-nine million, five hundred twenty-one thousand, eight hundred sixty-four".