21950317638 has 48 divisors (see below), whose sum is σ = 48977510400. Its totient is φ = 7101684720.

The previous prime is 21950317621. The next prime is 21950317681. The reversal of 21950317638 is 83671305912.

21950317638 is a `hidden beast` number, since 2 + 1 + 9 + 5 + 0 + 3 + 1 + 7 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21950317593 and 21950317602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46918 + ... + 214713.

It is an arithmetic number, because the mean of its divisors is an integer number (1020364800).

Almost surely, 2^21950317638 is an apocalyptic number.

21950317638 is an abundant number, since it is smaller than the sum of its proper divisors (27027192762).

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

21950317638 is a wasteful number, since it uses less digits than its factorization.

21950317638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261777 (or 261774 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 21950317638 in words is "twenty-one billion, nine hundred fifty million, three hundred seventeen thousand, six hundred thirty-eight".