138578690 has 16 divisors (see below), whose sum is σ = 256183992. Its totient is φ = 53933184.

The previous prime is 138578683. The next prime is 138578731. The reversal of 138578690 is 96875831.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 137851081 + 727609 = 11741^2 + 853^2 .

It is a super-2 number, since 2×138578690² = 38408106644232200, which contains 22 as substring.

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, 186899 + ... + 187638.

Almost surely, 2^138578690 is an apocalyptic number.

138578690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138578690 is a deficient number, since it is larger than the sum of its proper divisors (117605302).

138578690 is a wasteful number, since it uses less digits than its factorization.

138578690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374581.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 138578690 is about 11771.9450389475. The cubic root of 138578690 is about 517.4862529118.

The spelling of 138578690 in words is "one hundred thirty-eight million, five hundred seventy-eight thousand, six hundred ninety".