138357778 has 16 divisors (see below), whose sum is σ = 223891416. Its totient is φ = 63745920.

The previous prime is 138357721. The next prime is 138357787. The reversal of 138357778 is 877753831.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 70509609 + 67848169 = 8397^2 + 8237^2 .

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, 11598 + ... + 20278.

Almost surely, 2^138357778 is an apocalyptic number.

138357778 is a deficient number, since it is larger than the sum of its proper divisors (85533638).

138357778 is a wasteful number, since it uses less digits than its factorization.

138357778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9309.

The product of its digits is 987840, while the sum is 49.

The square root of 138357778 is about 11762.5583101637. The cubic root of 138357778 is about 517.2111271013.

The spelling of 138357778 in words is "one hundred thirty-eight million, three hundred fifty-seven thousand, seven hundred seventy-eight".