157906666 has 4 divisors (see below), whose sum is σ = 236860002. Its totient is φ = 78953332.

The previous prime is 157906643. The next prime is 157906667. The reversal of 157906666 is 666609751.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 142922025 + 14984641 = 11955^2 + 3871^2 .

It is not an unprimeable number, because it can be changed into a prime (157906667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39476665 + ... + 39476668.

Almost surely, 2^157906666 is an apocalyptic number.

157906666 is a deficient number, since it is larger than the sum of its proper divisors (78953336).

157906666 is an equidigital number, since it uses as much as digits as its factorization.

157906666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78953335.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 157906666 is about 12566.0919143543. The cubic root of 157906666 is about 540.5055462232.

The spelling of 157906666 in words is "one hundred fifty-seven million, nine hundred six thousand, six hundred sixty-six".