20402523 has 32 divisors (see below), whose sum is σ = 32275200. Its totient is φ = 12859560.

The previous prime is 20402521. The next prime is 20402531. The reversal of 20402523 is 32520402.

It is not a de Polignac number, because 20402523 - 2¹ = 20402521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20402496 and 20402505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402521) 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, 41308 + ... + 41798.

It is an arithmetic number, because the mean of its divisors is an integer number (1008600).

Almost surely, 2^20402523 is an apocalyptic number.

20402523 is a deficient number, since it is larger than the sum of its proper divisors (11872677).

20402523 is an frugal number, since it uses more digits than its factorization.

20402523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 18.

The square root of 20402523 is about 4516.9152084138. The cubic root of 20402523 is about 273.2507055750.

Adding to 20402523 its reverse (32520402), we get a palindrome (52922925).

The spelling of 20402523 in words is "twenty million, four hundred two thousand, five hundred twenty-three".