20890785 has 32 divisors (see below), whose sum is σ = 36725760. Its totient is φ = 10093248.

The previous prime is 20890783. The next prime is 20890789. The reversal of 20890785 is 58709802.

It is not a de Polignac number, because 20890785 - 2¹ = 20890783 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20890781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4962 + ... + 8148.

It is an arithmetic number, because the mean of its divisors is an integer number (1147680).

Almost surely, 2^20890785 is an apocalyptic number.

It is an amenable number.

20890785 is a deficient number, since it is larger than the sum of its proper divisors (15834975).

20890785 is a wasteful number, since it uses less digits than its factorization.

20890785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3237.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 20890785 is about 4570.6438277337. The cubic root of 20890785 is about 275.4133068904.

The spelling of 20890785 in words is "twenty million, eight hundred ninety thousand, seven hundred eighty-five".