138891666610 has 16 divisors (see below), whose sum is σ = 253429727256. Its totient is φ = 54795616128.

The previous prime is 138891666601. The next prime is 138891666611. The reversal of 138891666610 is 16666198831.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 66320155729 + 72571510881 = 257527^2 + 269391^2 .

It is not an unprimeable number, because it can be changed into a prime (138891666611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95130549 + ... + 95132008.

Almost surely, 2^138891666610 is an apocalyptic number.

138891666610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138891666610 is a deficient number, since it is larger than the sum of its proper divisors (114538060646).

138891666610 is a wasteful number, since it uses less digits than its factorization.

138891666610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190262637.

The product of its (nonzero) digits is 2239488, while the sum is 55.

The spelling of 138891666610 in words is "one hundred thirty-eight billion, eight hundred ninety-one million, six hundred sixty-six thousand, six hundred ten".