21554869017 has 32 divisors (see below), whose sum is σ = 31916021760. Its totient is φ = 12829219520.

The previous prime is 21554869013. The next prime is 21554869031. The reversal of 21554869017 is 71096845512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21554869017 - 2² = 21554869013 is a prime.

It is a super-2 number, since 2×21554869017² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21554869013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2142523 + ... + 2152559.

It is an arithmetic number, because the mean of its divisors is an integer number (997375680).

Almost surely, 2^21554869017 is an apocalyptic number.

It is an amenable number.

21554869017 is a deficient number, since it is larger than the sum of its proper divisors (10361152743).

21554869017 is a wasteful number, since it uses less digits than its factorization.

21554869017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11213.

The product of its (nonzero) digits is 604800, while the sum is 48.

The spelling of 21554869017 in words is "twenty-one billion, five hundred fifty-four million, eight hundred sixty-nine thousand, seventeen".