20642861 has 8 divisors (see below), whose sum is σ = 21215040. Its totient is φ = 20078208.

The previous prime is 20642857. The next prime is 20642899. The reversal of 20642861 is 16824602.

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 20642861 - 2² = 20642857 is a prime.

It is a super-2 number, since 2×20642861² = 852255420530642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642821) 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, 3920 + ... + 7526.

It is an arithmetic number, because the mean of its divisors is an integer number (2651880).

Almost surely, 2^20642861 is an apocalyptic number.

It is an amenable number.

20642861 is a deficient number, since it is larger than the sum of its proper divisors (572179).

20642861 is an equidigital number, since it uses as much as digits as its factorization.

20642861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3763.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 20642861 is about 4543.4415369849. The cubic root of 20642861 is about 274.3194677144.

The spelling of 20642861 in words is "twenty million, six hundred forty-two thousand, eight hundred sixty-one".