646738133 has 16 divisors (see below), whose sum is σ = 674558976. Its totient is φ = 619539840.

The previous prime is 646738129. The next prime is 646738177. The reversal of 646738133 is 331837646.

It is not a de Polignac number, because 646738133 - 2² = 646738129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646738733) 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, 849473 + ... + 850233.

It is an arithmetic number, because the mean of its divisors is an integer number (42159936).

Almost surely, 2^646738133 is an apocalyptic number.

It is an amenable number.

646738133 is a deficient number, since it is larger than the sum of its proper divisors (27820843).

646738133 is a wasteful number, since it uses less digits than its factorization.

646738133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124.

The product of its digits is 217728, while the sum is 41.

The square root of 646738133 is about 25431.0466359527. The cubic root of 646738133 is about 864.7876712744.

The spelling of 646738133 in words is "six hundred forty-six million, seven hundred thirty-eight thousand, one hundred thirty-three".