21495554517 has 4 divisors (see below), whose sum is σ = 28660739360. Its totient is φ = 14330369676.

The previous prime is 21495554513. The next prime is 21495554537. The reversal of 21495554517 is 71545559412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21495554517 - 2² = 21495554513 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21495554513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3582592417 + ... + 3582592422.

It is an arithmetic number, because the mean of its divisors is an integer number (7165184840).

Almost surely, 2^21495554517 is an apocalyptic number.

It is an amenable number.

21495554517 is a deficient number, since it is larger than the sum of its proper divisors (7165184843).

21495554517 is an equidigital number, since it uses as much as digits as its factorization.

21495554517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7165184842.

The product of its digits is 1260000, while the sum is 48.

The spelling of 21495554517 in words is "twenty-one billion, four hundred ninety-five million, five hundred fifty-four thousand, five hundred seventeen".