20890433 has 4 divisors (see below), whose sum is σ = 22119300. Its totient is φ = 19661568.

The previous prime is 20890409. The next prime is 20890447. The reversal of 20890433 is 33409802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 33409802 = 2 ⋅16704901.

It can be written as a sum of positive squares in 2 ways, for example, as 6091024 + 14799409 = 2468^2 + 3847^2 .

It is a cyclic number.

It is not a de Polignac number, because 20890433 - 2⁶ = 20890369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20890396 and 20890405.

It is not an unprimeable number, because it can be changed into a prime (20890453) 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, 614408 + ... + 614441.

It is an arithmetic number, because the mean of its divisors is an integer number (5529825).

Almost surely, 2^20890433 is an apocalyptic number.

It is an amenable number.

20890433 is a deficient number, since it is larger than the sum of its proper divisors (1228867).

20890433 is a wasteful number, since it uses less digits than its factorization.

20890433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228866.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20890433 is about 4570.6053209613. The cubic root of 20890433 is about 275.4117600197.

The spelling of 20890433 in words is "twenty million, eight hundred ninety thousand, four hundred thirty-three".