20431551616 has 32 divisors (see below), whose sum is σ = 46518266880. Its totient is φ = 8756378880.

The previous prime is 20431551611. The next prime is 20431551617. The reversal of 20431551616 is 61615513402.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×20431551616² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20431551611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11400640 + ... + 11402431.

It is an arithmetic number, because the mean of its divisors is an integer number (1453695840).

Almost surely, 2^20431551616 is an apocalyptic number.

It is an amenable number.

20431551616 is an abundant number, since it is smaller than the sum of its proper divisors (26086715264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20431551616 is an equidigital number, since it uses as much as digits as its factorization.

20431551616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22803092 (or 22803080 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 20431551616 in words is "twenty billion, four hundred thirty-one million, five hundred fifty-one thousand, six hundred sixteen".