1538438920 has 16 divisors (see below), whose sum is σ = 3461487660. Its totient is φ = 615375552.

The previous prime is 1538438899. The next prime is 1538438929. The reversal of 1538438920 is 298348351.

It can be written as a sum of positive squares in 2 ways, for example, as 1273205124 + 265233796 = 35682^2 + 16286^2 .

It is a super-3 number, since 3×1538438920³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1538438929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19230447 + ... + 19230526.

Almost surely, 2^1538438920 is an apocalyptic number.

1538438920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1538438920 is an abundant number, since it is smaller than the sum of its proper divisors (1923048740).

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

1538438920 is a wasteful number, since it uses less digits than its factorization.

1538438920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38460984 (or 38460980 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 1538438920 is about 39222.9386966352. The cubic root of 1538438920 is about 1154.4100158302.

The spelling of 1538438920 in words is "one billion, five hundred thirty-eight million, four hundred thirty-eight thousand, nine hundred twenty".