20521953 has 12 divisors (see below), whose sum is σ = 29690388. Its totient is φ = 13659360.

The previous prime is 20521889. The next prime is 20521967. The reversal of 20521953 is 35912502.

It can be written as a sum of positive squares in 2 ways, for example, as 10712529 + 9809424 = 3273^2 + 3132^2 .

It is not a de Polignac number, because 20521953 - 2⁶ = 20521889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20521153) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5743 + ... + 8603.

It is an arithmetic number, because the mean of its divisors is an integer number (2474199).

Almost surely, 2^20521953 is an apocalyptic number.

It is an amenable number.

20521953 is a deficient number, since it is larger than the sum of its proper divisors (9168435).

20521953 is a wasteful number, since it uses less digits than its factorization.

20521953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3664 (or 3661 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 20521953 is about 4530.1162236746. The cubic root of 20521953 is about 273.7828433729.

It can be divided in two parts, 2052 and 1953, that added together give a triangular number (4005 = T₈₉).

The spelling of 20521953 in words is "twenty million, five hundred twenty-one thousand, nine hundred fifty-three".