636038677021 has 16 divisors (see below), whose sum is σ = 701891930880. Its totient is φ = 571528376320.

The previous prime is 636038677009. The next prime is 636038677039. The reversal of 636038677021 is 120776830636.

It is a happy number.

It is not a de Polignac number, because 636038677021 - 2¹³ = 636038668829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636038672021) 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, 2852061 + ... + 3066973.

It is an arithmetic number, because the mean of its divisors is an integer number (43868245680).

Almost surely, 2^636038677021 is an apocalyptic number.

It is an amenable number.

636038677021 is a deficient number, since it is larger than the sum of its proper divisors (65853253859).

636038677021 is a wasteful number, since it uses less digits than its factorization.

636038677021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218036.

The product of its (nonzero) digits is 1524096, while the sum is 49.

The spelling of 636038677021 in words is "six hundred thirty-six billion, thirty-eight million, six hundred seventy-seven thousand, twenty-one".