664021954 has 8 divisors (see below), whose sum is σ = 998334540. Its totient is φ = 331243776.

The previous prime is 664021949. The next prime is 664021957. The reversal of 664021954 is 459120466.

It can be written as a sum of positive squares in 2 ways, for example, as 610337025 + 53684929 = 24705^2 + 7327^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (664021957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 382519 + ... + 384250.

Almost surely, 2^664021954 is an apocalyptic number.

664021954 is a deficient number, since it is larger than the sum of its proper divisors (334312586).

664021954 is a wasteful number, since it uses less digits than its factorization.

664021954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767204.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 664021954 is about 25768.6234401452. The cubic root of 664021954 is about 872.4237491348.

The spelling of 664021954 in words is "six hundred sixty-four million, twenty-one thousand, nine hundred fifty-four".