20702745 has 72 divisors (see below), whose sum is σ = 42948360. Its totient is φ = 9192960.

The previous prime is 20702743. The next prime is 20702767. The reversal of 20702745 is 54720702.

It can be written as a sum of positive squares in 4 ways, for example, as 1806336 + 18896409 = 1344^2 + 4347^2 .

It is not a de Polignac number, because 20702745 - 2¹ = 20702743 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20702741) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 90291 + ... + 90519.

It is an arithmetic number, because the mean of its divisors is an integer number (596505).

Almost surely, 2^20702745 is an apocalyptic number.

It is an amenable number.

20702745 is an abundant number, since it is smaller than the sum of its proper divisors (22245615).

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

20702745 is a wasteful number, since it uses less digits than its factorization.

20702745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 27.

The square root of 20702745 is about 4550.0269229973. The cubic root of 20702745 is about 274.5844743845.

The spelling of 20702745 in words is "twenty million, seven hundred two thousand, seven hundred forty-five".