251330666 has 4 divisors (see below), whose sum is σ = 376996002. Its totient is φ = 125665332.

The previous prime is 251330663. The next prime is 251330693. The reversal of 251330666 is 666033152.

251330666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 235162225 + 16168441 = 15335^2 + 4021^2 .

It is not an unprimeable number, because it can be changed into a prime (251330663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62832665 + ... + 62832668.

Almost surely, 2^251330666 is an apocalyptic number.

251330666 is a deficient number, since it is larger than the sum of its proper divisors (125665336).

251330666 is a wasteful number, since it uses less digits than its factorization.

251330666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125665335.

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 251330666 is about 15853.4118094497. The cubic root of 251330666 is about 631.0762371647.

The spelling of 251330666 in words is "two hundred fifty-one million, three hundred thirty thousand, six hundred sixty-six".