638372774261 has 16 divisors (see below), whose sum is σ = 642327766080. Its totient is φ = 634434353280.

The previous prime is 638372774243. The next prime is 638372774269. The reversal of 638372774261 is 162477273836.

It is a happy number.

638372774261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 638372774261 - 2¹⁰ = 638372773237 is a prime.

It is a super-2 number, since 2×638372774261² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638372774197 and 638372774206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638372774269) 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, 131322971 + ... + 131327831.

It is an arithmetic number, because the mean of its divisors is an integer number (40145485380).

Almost surely, 2^638372774261 is an apocalyptic number.

It is an amenable number.

638372774261 is a deficient number, since it is larger than the sum of its proper divisors (3954991819).

638372774261 is a wasteful number, since it uses less digits than its factorization.

638372774261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6404.

The product of its digits is 14224896, while the sum is 56.

The spelling of 638372774261 in words is "six hundred thirty-eight billion, three hundred seventy-two million, seven hundred seventy-four thousand, two hundred sixty-one".