21554080537 has 6 divisors (see below), whose sum is σ = 23691675434. Its totient is φ = 19594618560.

The previous prime is 21554080519. The next prime is 21554080543. The reversal of 21554080537 is 73508045512.

It can be written as a sum of positive squares in only one way, i.e., 10791885456 + 10762195081 = 103884^2 + 103741^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21554080537 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21554080537.

It is not an unprimeable number, because it can be changed into a prime (21554080517) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89066328 + ... + 89066569.

Almost surely, 2^21554080537 is an apocalyptic number.

It is an amenable number.

21554080537 is a deficient number, since it is larger than the sum of its proper divisors (2137594897).

21554080537 is a wasteful number, since it uses less digits than its factorization.

21554080537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178132919 (or 178132908 counting only the distinct ones).

The product of its (nonzero) digits is 168000, while the sum is 40.

The spelling of 21554080537 in words is "twenty-one billion, five hundred fifty-four million, eighty thousand, five hundred thirty-seven".