646447633 has 4 divisors (see below), whose sum is σ = 696174388. Its totient is φ = 596720880.

The previous prime is 646447603. The next prime is 646447709. The reversal of 646447633 is 336744646.

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

It can be written as a sum of positive squares in 2 ways, for example, as 297804049 + 348643584 = 17257^2 + 18672^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646447633 is a prime.

It is a super-2 number, since 2×646447633² = 835789084422605378, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 646447633.

It is not an unprimeable number, because it can be changed into a prime (646447603) 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, 24863358 + ... + 24863383.

It is an arithmetic number, because the mean of its divisors is an integer number (174043597).

Almost surely, 2^646447633 is an apocalyptic number.

It is an amenable number.

646447633 is a deficient number, since it is larger than the sum of its proper divisors (49726755).

646447633 is a wasteful number, since it uses less digits than its factorization.

646447633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49726754.

The product of its digits is 870912, while the sum is 43.

The square root of 646447633 is about 25425.3344717429. The cubic root of 646447633 is about 864.6581709253.

The spelling of 646447633 in words is "six hundred forty-six million, four hundred forty-seven thousand, six hundred thirty-three".