20890481 has 4 divisors (see below), whose sum is σ = 21990000. Its totient is φ = 19790964.

The previous prime is 20890453. The next prime is 20890489. The reversal of 20890481 is 18409802.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18409802 = 2 ⋅9204901.

It is a cyclic number.

It is not a de Polignac number, because 20890481 - 2¹⁸ = 20628337 is a prime.

It is a super-2 number, since 2×20890481² = 872824392822722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20890489) 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, 549731 + ... + 549768.

It is an arithmetic number, because the mean of its divisors is an integer number (5497500).

Almost surely, 2^20890481 is an apocalyptic number.

It is an amenable number.

20890481 is a deficient number, since it is larger than the sum of its proper divisors (1099519).

20890481 is a wasteful number, since it uses less digits than its factorization.

20890481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099518.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 20890481 is about 4570.6105719039. The cubic root of 20890481 is about 275.4119709577.

The spelling of 20890481 in words is "twenty million, eight hundred ninety thousand, four hundred eighty-one".