20516314643 has 16 divisors (see below), whose sum is σ = 22560270336. Its totient is φ = 18502590240.

The previous prime is 20516314633. The next prime is 20516314661. The reversal of 20516314643 is 34641361502.

It is a cyclic number.

It is not a de Polignac number, because 20516314643 - 2¹⁸ = 20516052499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20516314633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 988430 + ... + 1008972.

It is an arithmetic number, because the mean of its divisors is an integer number (1410016896).

Almost surely, 2^20516314643 is an apocalyptic number.

20516314643 is a deficient number, since it is larger than the sum of its proper divisors (2043955693).

20516314643 is a wasteful number, since it uses less digits than its factorization.

20516314643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21274.

The product of its (nonzero) digits is 51840, while the sum is 35.

The spelling of 20516314643 in words is "twenty billion, five hundred sixteen million, three hundred fourteen thousand, six hundred forty-three".