645633403406 has 8 divisors (see below), whose sum is σ = 968465623320. Its totient is φ = 322811528968.

The previous prime is 645633403357. The next prime is 645633403439. The reversal of 645633403406 is 604304336546.

It is a happy number.

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

It is a super-2 number, since 2×645633403406² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2428421 + ... + 2681136.

It is an arithmetic number, because the mean of its divisors is an integer number (121058202915).

Almost surely, 2^645633403406 is an apocalyptic number.

645633403406 is a deficient number, since it is larger than the sum of its proper divisors (322832219914).

645633403406 is a wasteful number, since it uses less digits than its factorization.

645633403406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5172738.

The product of its (nonzero) digits is 1866240, while the sum is 44.

The spelling of 645633403406 in words is "six hundred forty-five billion, six hundred thirty-three million, four hundred three thousand, four hundred six".