64401994 has 4 divisors (see below), whose sum is σ = 96602994. Its totient is φ = 32200996.

The previous prime is 64401991. The next prime is 64402007. The reversal of 64401994 is 49910446.

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., 64400625 + 1369 = 8025^2 + 37^2 .

It is not an unprimeable number, because it can be changed into a prime (64401991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16100497 + ... + 16100500.

Almost surely, 2^64401994 is an apocalyptic number.

64401994 is a deficient number, since it is larger than the sum of its proper divisors (32201000).

64401994 is a wasteful number, since it uses less digits than its factorization.

64401994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32200999.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 64401994 is about 8025.0852954969. The cubic root of 64401994 is about 400.8357401300.

The spelling of 64401994 in words is "sixty-four million, four hundred one thousand, nine hundred ninety-four".