20386561 has 8 divisors (see below), whose sum is σ = 22663424. Its totient is φ = 18210960.

The previous prime is 20386549. The next prime is 20386567. The reversal of 20386561 is 16568302.

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

It is a cyclic number.

It is not a de Polignac number, because 20386561 - 2⁵ = 20386529 is a prime.

It is a super-2 number, since 2×20386561² = 831223738813442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20386567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24891 + ... + 25696.

It is an arithmetic number, because the mean of its divisors is an integer number (2832928).

Almost surely, 2^20386561 is an apocalyptic number.

It is an amenable number.

20386561 is a deficient number, since it is larger than the sum of its proper divisors (2276863).

20386561 is a wasteful number, since it uses less digits than its factorization.

20386561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50631.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20386561 is about 4515.1479488495. The cubic root of 20386561 is about 273.1794273692.

The spelling of 20386561 in words is "twenty million, three hundred eighty-six thousand, five hundred sixty-one".