138770820 has 60 divisors (see below), whose sum is σ = 435334284. Its totient is φ = 37005120.

The previous prime is 138770777. The next prime is 138770833. The reversal of 138770820 is 28077831.

It can be written as a sum of positive squares in 2 ways, for example, as 25220484 + 113550336 = 5022^2 + 10656^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 41211 + ... + 44450.

Almost surely, 2^138770820 is an apocalyptic number.

138770820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138770820 is an abundant number, since it is smaller than the sum of its proper divisors (296563464).

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

138770820 is a wasteful number, since it uses less digits than its factorization.

138770820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85682 (or 85671 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 138770820 is about 11780.1027160208. The cubic root of 138770820 is about 517.7252957272.

The spelling of 138770820 in words is "one hundred thirty-eight million, seven hundred seventy thousand, eight hundred twenty".