20868215261 has 16 divisors (see below), whose sum is σ = 22952816640. Its totient is φ = 18884582640.

The previous prime is 20868215239. The next prime is 20868215279. The reversal of 20868215261 is 16251286802.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20868215261 - 2¹⁴ = 20868198877 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 (20868215201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 292556 + ... + 356826.

It is an arithmetic number, because the mean of its divisors is an integer number (1434551040).

Almost surely, 2^20868215261 is an apocalyptic number.

It is an amenable number.

20868215261 is a deficient number, since it is larger than the sum of its proper divisors (2084601379).

20868215261 is a wasteful number, since it uses less digits than its factorization.

20868215261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65056.

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 20868215261 in words is "twenty billion, eight hundred sixty-eight million, two hundred fifteen thousand, two hundred sixty-one".