634491989761 has 16 divisors (see below), whose sum is σ = 731964196480. Its totient is φ = 538729833600.

The previous prime is 634491989753. The next prime is 634491989777. The reversal of 634491989761 is 167989194436.

It is not a de Polignac number, because 634491989761 - 2³ = 634491989753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634491989711) 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, 3106390 + ... + 3304336.

It is an arithmetic number, because the mean of its divisors is an integer number (45747762280).

Almost surely, 2^634491989761 is an apocalyptic number.

It is an amenable number.

634491989761 is a deficient number, since it is larger than the sum of its proper divisors (97472206719).

634491989761 is a wasteful number, since it uses less digits than its factorization.

634491989761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202264.

The product of its digits is 70543872, while the sum is 67.

The spelling of 634491989761 in words is "six hundred thirty-four billion, four hundred ninety-one million, nine hundred eighty-nine thousand, seven hundred sixty-one".