1538439040 has 64 divisors (see below), whose sum is σ = 3689919360. Its totient is φ = 613353472.

The previous prime is 1538439029. The next prime is 1538439061. The reversal of 1538439040 is 409348351.

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

It is a super-2 number, since 2×1538439040² = 4733589359592243200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199089 + ... + 206671.

It is an arithmetic number, because the mean of its divisors is an integer number (57654990).

Almost surely, 2^1538439040 is an apocalyptic number.

1538439040 is a gapful number since it is divisible by the number (10) 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 1538439040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1844959680).

1538439040 is an abundant number, since it is smaller than the sum of its proper divisors (2151480320).

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

1538439040 is an equidigital number, since it uses as much as digits as its factorization.

1538439040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7919 (or 7907 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 1538439040 is about 39222.9402263522. The cubic root of 1538439040 is about 1154.4100458453.

The spelling of 1538439040 in words is "one billion, five hundred thirty-eight million, four hundred thirty-nine thousand, forty".