646436451 has 4 divisors (see below), whose sum is σ = 861915272. Its totient is φ = 430957632.

The previous prime is 646436443. The next prime is 646436467. The reversal of 646436451 is 154634646.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 646436451 - 2³ = 646436443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646436431) 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, 107739406 + ... + 107739411.

It is an arithmetic number, because the mean of its divisors is an integer number (215478818).

Almost surely, 2^646436451 is an apocalyptic number.

646436451 is a deficient number, since it is larger than the sum of its proper divisors (215478821).

646436451 is a wasteful number, since it uses less digits than its factorization.

646436451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215478820.

The product of its digits is 207360, while the sum is 39.

The square root of 646436451 is about 25425.1145720132. The cubic root of 646436451 is about 864.6531853895.

The spelling of 646436451 in words is "six hundred forty-six million, four hundred thirty-six thousand, four hundred fifty-one".