1640635722 has 160 divisors (see below), whose sum is σ = 4171305600. Its totient is φ = 477601920.

The previous prime is 1640635709. The next prime is 1640635729. The reversal of 1640635722 is 2275360461.

1640635722 is a `hidden beast` number, since 1 + 640 + 6 + 3 + 5 + 7 + 2 + 2 = 666.

It is a super-2 number, since 2×1640635722² = 5383371144604922568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1640635729) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 9824083 + ... + 9824249.

It is an arithmetic number, because the mean of its divisors is an integer number (26070660).

Almost surely, 2^1640635722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640635722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2085652800).

1640635722 is an abundant number, since it is smaller than the sum of its proper divisors (2530669878).

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

1640635722 is a wasteful number, since it uses less digits than its factorization.

1640635722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378 (or 369 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 1640635722 is about 40504.7617200743. The cubic root of 1640635722 is about 1179.4260643746.

The spelling of 1640635722 in words is "one billion, six hundred forty million, six hundred thirty-five thousand, seven hundred twenty-two".