642878199 has 12 divisors (see below), whose sum is σ = 942462456. Its totient is φ = 422188272.

The previous prime is 642878183. The next prime is 642878209. The reversal of 642878199 is 991878246.

It is not a de Polignac number, because 642878199 - 2⁴ = 642878183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642879199) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 532464 + ... + 533669.

It is an arithmetic number, because the mean of its divisors is an integer number (78538538).

Almost surely, 2^642878199 is an apocalyptic number.

642878199 is a deficient number, since it is larger than the sum of its proper divisors (299584257).

642878199 is a wasteful number, since it uses less digits than its factorization.

642878199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066206 (or 1066203 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 642878199 is about 25355.0428711923. The cubic root of 642878199 is about 863.0637967220.

The spelling of 642878199 in words is "six hundred forty-two million, eight hundred seventy-eight thousand, one hundred ninety-nine".