21894946261 has 4 divisors (see below), whose sum is σ = 22052464000. Its totient is φ = 21737428524.

The previous prime is 21894946237. The next prime is 21894946273. The reversal of 21894946261 is 16264949812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21894946261 - 2²⁷ = 21760728533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21894946199 and 21894946208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21894946361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78758661 + ... + 78758938.

It is an arithmetic number, because the mean of its divisors is an integer number (5513116000).

Almost surely, 2^21894946261 is an apocalyptic number.

It is an amenable number.

21894946261 is a deficient number, since it is larger than the sum of its proper divisors (157517739).

21894946261 is a wasteful number, since it uses less digits than its factorization.

21894946261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157517738.

The product of its digits is 1492992, while the sum is 52.

The spelling of 21894946261 in words is "twenty-one billion, eight hundred ninety-four million, nine hundred forty-six thousand, two hundred sixty-one".