640366154 has 4 divisors (see below), whose sum is σ = 960549234. Its totient is φ = 320183076.

The previous prime is 640366127. The next prime is 640366169. The reversal of 640366154 is 451663046.

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., 388287025 + 252079129 = 19705^2 + 15877^2 .

It is a super-2 number, since 2×640366154² = 820137622377503432, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160091537 + ... + 160091540.

Almost surely, 2^640366154 is an apocalyptic number.

640366154 is a deficient number, since it is larger than the sum of its proper divisors (320183080).

640366154 is a wasteful number, since it uses less digits than its factorization.

640366154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320183079.

The product of its (nonzero) digits is 51840, while the sum is 35.

The square root of 640366154 is about 25305.4570004179. The cubic root of 640366154 is about 861.9381894479.

The spelling of 640366154 in words is "six hundred forty million, three hundred sixty-six thousand, one hundred fifty-four".