1387899990 has 24 divisors (see below), whose sum is σ = 3608540208. Its totient is φ = 370106640.

The previous prime is 1387899967. The next prime is 1387899991. The reversal of 1387899990 is 999987831.

1387899990 is a `hidden beast` number, since 1 + 387 + 89 + 99 + 90 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387899991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7710466 + ... + 7710645.

It is an arithmetic number, because the mean of its divisors is an integer number (150355842).

Almost surely, 2^1387899990 is an apocalyptic number.

1387899990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1387899990 is an abundant number, since it is smaller than the sum of its proper divisors (2220640218).

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

1387899990 is a wasteful number, since it uses less digits than its factorization.

1387899990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15421124 (or 15421121 counting only the distinct ones).

The product of its (nonzero) digits is 8817984, while the sum is 63.

The square root of 1387899990 is about 37254.5297916911. The cubic root of 1387899990 is about 1115.4567199986.

The spelling of 1387899990 in words is "one billion, three hundred eighty-seven million, eight hundred ninety-nine thousand, nine hundred ninety".