640951466 has 4 divisors (see below), whose sum is σ = 961427202. Its totient is φ = 320475732.

The previous prime is 640951463. The next prime is 640951499. The reversal of 640951466 is 664159046.

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., 637815025 + 3136441 = 25255^2 + 1771^2 .

It is not an unprimeable number, because it can be changed into a prime (640951463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160237865 + ... + 160237868.

Almost surely, 2^640951466 is an apocalyptic number.

640951466 is a deficient number, since it is larger than the sum of its proper divisors (320475736).

640951466 is a wasteful number, since it uses less digits than its factorization.

640951466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320475735.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 640951466 is about 25317.0192953278. The cubic root of 640951466 is about 862.2007210899.

It can be divided in two parts, 6409 and 51466, that added together give a palindrome (57875).

The spelling of 640951466 in words is "six hundred forty million, nine hundred fifty-one thousand, four hundred sixty-six".