20661420551 has 8 divisors (see below), whose sum is σ = 20952115200. Its totient is φ = 20371455000.

The previous prime is 20661420541. The next prime is 20661420557. The reversal of 20661420551 is 15502416602.

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 20661420551 - 2³⁰ = 19587678727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661420557) 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, 125075 + ... + 238676.

It is an arithmetic number, because the mean of its divisors is an integer number (2619014400).

Almost surely, 2^20661420551 is an apocalyptic number.

20661420551 is a deficient number, since it is larger than the sum of its proper divisors (290694649).

20661420551 is an equidigital number, since it uses as much as digits as its factorization.

20661420551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364549.

The product of its (nonzero) digits is 14400, while the sum is 32.

The spelling of 20661420551 in words is "twenty billion, six hundred sixty-one million, four hundred twenty thousand, five hundred fifty-one".