21554113501 has 2 divisors, whose sum is σ = 21554113502. Its totient is φ = 21554113500.

The previous prime is 21554113499. The next prime is 21554113507. The reversal of 21554113501 is 10531145512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16608507876 + 4945605625 = 128874^2 + 70325^2 .

It is a cyclic number.

It is not a de Polignac number, because 21554113501 - 2¹ = 21554113499 is a prime.

Together with 21554113499, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21554113501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21554113507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10777056750 + 10777056751.

It is an arithmetic number, because the mean of its divisors is an integer number (10777056751).

Almost surely, 2^21554113501 is an apocalyptic number.

It is an amenable number.

21554113501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21554113501 is an equidigital number, since it uses as much as digits as its factorization.

21554113501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 21554113501 in words is "twenty-one billion, five hundred fifty-four million, one hundred thirteen thousand, five hundred one".