20902881 has 8 divisors (see below), whose sum is σ = 28831680. Its totient is φ = 13454672.

The previous prime is 20902879. The next prime is 20902901. The reversal of 20902881 is 18820902.

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 20902881 - 2¹ = 20902879 is a prime.

It is a super-2 number, since 2×20902881² = 873860868200322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20902801) 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, 120045 + ... + 120218.

It is an arithmetic number, because the mean of its divisors is an integer number (3603960).

Almost surely, 2^20902881 is an apocalyptic number.

It is an amenable number.

20902881 is a deficient number, since it is larger than the sum of its proper divisors (7928799).

20902881 is a wasteful number, since it uses less digits than its factorization.

20902881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240295.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 20902881 is about 4571.9668633970. The cubic root of 20902881 is about 275.4664524375.

The spelling of 20902881 in words is "twenty million, nine hundred two thousand, eight hundred eighty-one".