138489690 has 64 divisors (see below), whose sum is σ = 338558976. Its totient is φ = 36251712.

The previous prime is 138489649. The next prime is 138489691. The reversal of 138489690 is 96984831.

It is a super-2 number, since 2×138489690² = 38358788472592200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138489691) 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, 620919 + ... + 621141.

It is an arithmetic number, because the mean of its divisors is an integer number (5289984).

Almost surely, 2^138489690 is an apocalyptic number.

138489690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138489690 is an abundant number, since it is smaller than the sum of its proper divisors (200069286).

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

138489690 is a wasteful number, since it uses less digits than its factorization.

138489690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523.

The product of its (nonzero) digits is 373248, while the sum is 48.

The square root of 138489690 is about 11768.1642578611. The cubic root of 138489690 is about 517.3754466985.

The spelling of 138489690 in words is "one hundred thirty-eight million, four hundred eighty-nine thousand, six hundred ninety".