634775408640 has 1456 divisors, whose sum is σ = 2517803444016. Its totient is φ = 152882380800.

The previous prime is 634775408621. The next prime is 634775408647. The reversal of 634775408640 is 46804577436.

634775408640 is a `hidden beast` number, since 6 + 3 + 477 + 54 + 0 + 86 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 149824733184 + 484950675456 = 387072^2 + 696384^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (634775408647) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 10406154210 + ... + 10406154270.

Almost surely, 2^634775408640 is an apocalyptic number.

634775408640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 634775408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1258901722008).

634775408640 is an abundant number, since it is smaller than the sum of its proper divisors (1883028035376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

634775408640 is an equidigital number, since it uses as much as digits as its factorization.

634775408640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 13547520, while the sum is 54.

The spelling of 634775408640 in words is "six hundred thirty-four billion, seven hundred seventy-five million, four hundred eight thousand, six hundred forty".