636421780 has 24 divisors (see below), whose sum is σ = 1336974408. Its totient is φ = 254475648.

The previous prime is 636421771. The next prime is 636421789. The reversal of 636421780 is 87124636.

636421780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (636421771) and next prime (636421789).

It can be written as a sum of positive squares in 4 ways, for example, as 93624976 + 542796804 = 9676^2 + 23298^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636421789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84322 + ... + 91558.

It is an arithmetic number, because the mean of its divisors is an integer number (55707267).

Almost surely, 2^636421780 is an apocalyptic number.

It is an amenable number.

636421780 is an abundant number, since it is smaller than the sum of its proper divisors (700552628).

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

636421780 is a wasteful number, since it uses less digits than its factorization.

636421780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11643 (or 11641 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 636421780 is about 25227.4013723174. The cubic root of 636421780 is about 860.1648232853.

The spelling of 636421780 in words is "six hundred thirty-six million, four hundred twenty-one thousand, seven hundred eighty".