20435865557 has 8 divisors (see below), whose sum is σ = 20834475480. Its totient is φ = 20037738240.

The previous prime is 20435865553. The next prime is 20435865589. The reversal of 20435865557 is 75556853402.

It can be written as a sum of positive squares in 4 ways, for example, as 10266958276 + 10168907281 = 101326^2 + 100841^2 .

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 20435865557 - 2² = 20435865553 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 (20435865553) 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, 34544 + ... + 205097.

It is an arithmetic number, because the mean of its divisors is an integer number (2604309435).

Almost surely, 2^20435865557 is an apocalyptic number.

It is an amenable number.

20435865557 is a deficient number, since it is larger than the sum of its proper divisors (398609923).

20435865557 is a wasteful number, since it uses less digits than its factorization.

20435865557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241303.

The product of its (nonzero) digits is 5040000, while the sum is 50.

The spelling of 20435865557 in words is "twenty billion, four hundred thirty-five million, eight hundred sixty-five thousand, five hundred fifty-seven".