20998587 has 8 divisors (see below), whose sum is σ = 29645136. Its totient is φ = 13175552.

The previous prime is 20998583. The next prime is 20998589. The reversal of 20998587 is 78589902.

It is a happy number.

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 20998587 - 2² = 20998583 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20998583) 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, 205818 + ... + 205919.

It is an arithmetic number, because the mean of its divisors is an integer number (3705642).

Almost surely, 2^20998587 is an apocalyptic number.

20998587 is a deficient number, since it is larger than the sum of its proper divisors (8646549).

20998587 is a wasteful number, since it uses less digits than its factorization.

20998587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411757.

The product of its (nonzero) digits is 362880, while the sum is 48.

The square root of 20998587 is about 4582.4215214229. The cubic root of 20998587 is about 275.8862296265.

The spelling of 20998587 in words is "twenty million, nine hundred ninety-eight thousand, five hundred eighty-seven".