20564398 has 4 divisors (see below), whose sum is σ = 30846600. Its totient is φ = 10282198.

The previous prime is 20564389. The next prime is 20564399. The reversal of 20564398 is 89346502.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5141098 + ... + 5141101.

It is an arithmetic number, because the mean of its divisors is an integer number (7711650).

Almost surely, 2^20564398 is an apocalyptic number.

20564398 is a deficient number, since it is larger than the sum of its proper divisors (10282202).

20564398 is a wasteful number, since it uses less digits than its factorization.

20564398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10282201.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 20564398 is about 4534.7985622296. The cubic root of 20564398 is about 273.9714659401.

The spelling of 20564398 in words is "twenty million, five hundred sixty-four thousand, three hundred ninety-eight".