137978666 has 16 divisors (see below), whose sum is σ = 238104960. Its totient is φ = 58741200.

The previous prime is 137978657. The next prime is 137978671. The reversal of 137978666 is 666879731.

137978666 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×137978666² = 38076224542279112, 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, 30521 + ... + 34748.

It is an arithmetic number, because the mean of its divisors is an integer number (14881560).

Almost surely, 2^137978666 is an apocalyptic number.

137978666 is a deficient number, since it is larger than the sum of its proper divisors (100126294).

137978666 is a wasteful number, since it uses less digits than its factorization.

137978666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65429.

The product of its digits is 2286144, while the sum is 53.

The square root of 137978666 is about 11746.4320540324. The cubic root of 137978666 is about 516.7382942434.

The spelling of 137978666 in words is "one hundred thirty-seven million, nine hundred seventy-eight thousand, six hundred sixty-six".