646738149 has 4 divisors (see below), whose sum is σ = 862317536. Its totient is φ = 431158764.

The previous prime is 646738129. The next prime is 646738177. The reversal of 646738149 is 941837646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 646738149 - 2²⁵ = 613183717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646738098 and 646738107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646738109) 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, 107789689 + ... + 107789694.

It is an arithmetic number, because the mean of its divisors is an integer number (215579384).

Almost surely, 2^646738149 is an apocalyptic number.

It is an amenable number.

646738149 is a deficient number, since it is larger than the sum of its proper divisors (215579387).

646738149 is a wasteful number, since it uses less digits than its factorization.

646738149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215579386.

The product of its digits is 870912, while the sum is 48.

The square root of 646738149 is about 25431.0469505288. The cubic root of 646738149 is about 864.7876784059.

The spelling of 646738149 in words is "six hundred forty-six million, seven hundred thirty-eight thousand, one hundred forty-nine".