21980887 has 8 divisors (see below), whose sum is σ = 22225280. Its totient is φ = 21738240.

The previous prime is 21980857. The next prime is 21980897. The reversal of 21980887 is 78808912.

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 21980887 - 2¹⁵ = 21948119 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 (21980837) 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, 53539 + ... + 53947.

It is an arithmetic number, because the mean of its divisors is an integer number (2778160).

Almost surely, 2^21980887 is an apocalyptic number.

21980887 is a deficient number, since it is larger than the sum of its proper divisors (244393).

21980887 is a wasteful number, since it uses less digits than its factorization.

21980887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 21980887 is about 4688.3778644644. The cubic root of 21980887 is about 280.1227650438.

The spelling of 21980887 in words is "twenty-one million, nine hundred eighty thousand, eight hundred eighty-seven".