20959785 has 96 divisors (see below), whose sum is σ = 47443968. Its totient is φ = 8300160.

The previous prime is 20959781. The next prime is 20959787. The reversal of 20959785 is 58795902.

It is a happy number.

It is not a de Polignac number, because 20959785 - 2² = 20959781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20959785.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20959781) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 79564 + ... + 79826.

It is an arithmetic number, because the mean of its divisors is an integer number (494208).

Almost surely, 2^20959785 is an apocalyptic number.

It is an amenable number.

20959785 is an abundant number, since it is smaller than the sum of its proper divisors (26484183).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20959785 is a wasteful number, since it uses less digits than its factorization.

20959785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The square root of 20959785 is about 4578.1857760471. The cubic root of 20959785 is about 275.7161937740.

It can be divided in two parts, 20 and 959785, that added together give a triangular number (959805 = T₁₃₈₅).

The spelling of 20959785 in words is "twenty million, nine hundred fifty-nine thousand, seven hundred eighty-five".