20856554431 has 8 divisors (see below), whose sum is σ = 22119097680. Its totient is φ = 19597976448.

The previous prime is 20856554413. The next prime is 20856554437. The reversal of 20856554431 is 13445565802.

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

It is not a de Polignac number, because 20856554431 - 2¹¹ = 20856552383 is a prime.

It is a super-2 number, since 2×20856554431² (a number of 21 digits) 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 (20856554437) 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, 980476 + ... + 1001521.

It is an arithmetic number, because the mean of its divisors is an integer number (2764887210).

Almost surely, 2^20856554431 is an apocalyptic number.

20856554431 is a deficient number, since it is larger than the sum of its proper divisors (1262543249).

20856554431 is a wasteful number, since it uses less digits than its factorization.

20856554431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1982633.

The product of its (nonzero) digits is 576000, while the sum is 43.

The spelling of 20856554431 in words is "twenty billion, eight hundred fifty-six million, five hundred fifty-four thousand, four hundred thirty-one".