20521994 has 8 divisors (see below), whose sum is σ = 30852900. Its totient is φ = 10237696.

The previous prime is 20521987. The next prime is 20522023. The reversal of 20521994 is 49912502.

It can be written as a sum of positive squares in 2 ways, for example, as 20205025 + 316969 = 4495^2 + 563^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20521994.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10529 + ... + 12324.

Almost surely, 2^20521994 is an apocalyptic number.

20521994 is a deficient number, since it is larger than the sum of its proper divisors (10330906).

20521994 is a wasteful number, since it uses less digits than its factorization.

20521994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23304.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 20521994 is about 4530.1207489426. The cubic root of 20521994 is about 273.7830256994.

The spelling of 20521994 in words is "twenty million, five hundred twenty-one thousand, nine hundred ninety-four".