20425661661 has 8 divisors (see below), whose sum is σ = 27251601664. Its totient is φ = 13608414720.

The previous prime is 20425661657. The next prime is 20425661671. The reversal of 20425661661 is 16616652402.

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

It is not a de Polignac number, because 20425661661 - 2² = 20425661657 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 (20425661671) 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, 2167780 + ... + 2177181.

It is an arithmetic number, because the mean of its divisors is an integer number (3406450208).

Almost surely, 2^20425661661 is an apocalyptic number.

It is an amenable number.

20425661661 is a deficient number, since it is larger than the sum of its proper divisors (6825940003).

20425661661 is a wasteful number, since it uses less digits than its factorization.

20425661661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4346531.

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 20425661661 in words is "twenty billion, four hundred twenty-five million, six hundred sixty-one thousand, six hundred sixty-one".