642928405 has 16 divisors (see below), whose sum is σ = 912136320. Its totient is φ = 425662272.

The previous prime is 642928387. The next prime is 642928409. The reversal of 642928405 is 504829246.

It is not a de Polignac number, because 642928405 - 2⁵ = 642928373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642928409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315699 + ... + 317728.

It is an arithmetic number, because the mean of its divisors is an integer number (57008520).

Almost surely, 2^642928405 is an apocalyptic number.

It is an amenable number.

642928405 is a deficient number, since it is larger than the sum of its proper divisors (269207915).

642928405 is a wasteful number, since it uses less digits than its factorization.

642928405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633468.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 642928405 is about 25356.0329113211. The cubic root of 642928405 is about 863.0862633173.

The spelling of 642928405 in words is "six hundred forty-two million, nine hundred twenty-eight thousand, four hundred five".