642470399 has 4 divisors (see below), whose sum is σ = 654592536. Its totient is φ = 630348264.

The previous prime is 642470383. The next prime is 642470419. The reversal of 642470399 is 993074246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993074246 = 2 ⋅496537123.

It is a cyclic number.

It is not a de Polignac number, because 642470399 - 2⁴ = 642470383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642470099) 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, 6060989 + ... + 6061094.

It is an arithmetic number, because the mean of its divisors is an integer number (163648134).

Almost surely, 2^642470399 is an apocalyptic number.

642470399 is a deficient number, since it is larger than the sum of its proper divisors (12122137).

642470399 is a wasteful number, since it uses less digits than its factorization.

642470399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12122136.

The product of its (nonzero) digits is 326592, while the sum is 44.

The square root of 642470399 is about 25346.9998027380. Note that the first 3 decimals coincide. The cubic root of 642470399 is about 862.8812676609.

The spelling of 642470399 in words is "six hundred forty-two million, four hundred seventy thousand, three hundred ninety-nine".