21898957487 has 8 divisors (see below), whose sum is σ = 24217029840. Its totient is φ = 19635428160.

The previous prime is 21898957459. The next prime is 21898957499. The reversal of 21898957487 is 78475989812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21898957487 - 2¹⁰ = 21898956463 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 (21898957687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13634912 + ... + 13636517.

It is an arithmetic number, because the mean of its divisors is an integer number (3027128730).

Almost surely, 2^21898957487 is an apocalyptic number.

21898957487 is a deficient number, since it is larger than the sum of its proper divisors (2318072353).

21898957487 is a wasteful number, since it uses less digits than its factorization.

21898957487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27271513.

The product of its digits is 81285120, while the sum is 68.

The spelling of 21898957487 in words is "twenty-one billion, eight hundred ninety-eight million, nine hundred fifty-seven thousand, four hundred eighty-seven".