21938677517501 has 2 divisors, whose sum is σ = 21938677517502. Its totient is φ = 21938677517500.

The previous prime is 21938677517453. The next prime is 21938677517507. The reversal of 21938677517501 is 10571577683912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13721431020025 + 8217246497476 = 3704245^2 + 2866574^2 .

It is a cyclic number.

It is not a de Polignac number, because 21938677517501 - 2²² = 21938673323197 is a prime.

It is a super-2 number, since 2×21938677517501² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21938677517507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10969338758750 + 10969338758751.

It is an arithmetic number, because the mean of its divisors is an integer number (10969338758751).

Almost surely, 2^{21938677517501} is an apocalyptic number.

It is an amenable number.

21938677517501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21938677517501 is an equidigital number, since it uses as much as digits as its factorization.

21938677517501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22226400, while the sum is 62.

The spelling of 21938677517501 in words is "twenty-one trillion, nine hundred thirty-eight billion, six hundred seventy-seven million, five hundred seventeen thousand, five hundred one".