20781212759 has 16 divisors (see below), whose sum is σ = 21251496960. Its totient is φ = 20315470560.

The previous prime is 20781212729. The next prime is 20781212773. The reversal of 20781212759 is 95721218702.

It is a cyclic number.

It is not a de Polignac number, because 20781212759 - 2²⁴ = 20764435543 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 (20781212729) 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, 9956414 + ... + 9958500.

It is an arithmetic number, because the mean of its divisors is an integer number (1328218560).

Almost surely, 2^20781212759 is an apocalyptic number.

20781212759 is a deficient number, since it is larger than the sum of its proper divisors (470284201).

20781212759 is a wasteful number, since it uses less digits than its factorization.

20781212759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3070.

The product of its (nonzero) digits is 141120, while the sum is 44.

The spelling of 20781212759 in words is "twenty billion, seven hundred eighty-one million, two hundred twelve thousand, seven hundred fifty-nine".