634400649 has 6 divisors (see below), whose sum is σ = 916356506. Its totient is φ = 422933760.

The previous prime is 634400639. The next prime is 634400659. The reversal of 634400649 is 946004436.

634400649 is a `hidden beast` number, since 6 + 3 + 4 + 4 + 0 + 0 + 649 = 666.

It is an interprime number because it is at equal distance from previous prime (634400639) and next prime (634400659).

It can be written as a sum of positive squares in only one way, i.e., 357777225 + 276623424 = 18915^2 + 16632^2 .

It is not a de Polignac number, because 634400649 - 2⁵ = 634400617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634400609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35244472 + ... + 35244489.

Almost surely, 2^634400649 is an apocalyptic number.

It is an amenable number.

634400649 is a deficient number, since it is larger than the sum of its proper divisors (281955857).

634400649 is a wasteful number, since it uses less digits than its factorization.

634400649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70488967 (or 70488964 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 634400649 is about 25187.3112697644. The cubic root of 634400649 is about 859.2532949747.

The spelling of 634400649 in words is "six hundred thirty-four million, four hundred thousand, six hundred forty-nine".