21965428749 has 24 divisors (see below), whose sum is σ = 32204088000. Its totient is φ = 13307282560.

The previous prime is 21965428747. The next prime is 21965428753. The reversal of 21965428749 is 94782456912.

It is not a de Polignac number, because 21965428749 - 2¹ = 21965428747 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21965428747) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1078549 + ... + 1098725.

It is an arithmetic number, because the mean of its divisors is an integer number (1341837000).

Almost surely, 2^21965428749 is an apocalyptic number.

It is an amenable number.

21965428749 is a deficient number, since it is larger than the sum of its proper divisors (10238659251).

21965428749 is a wasteful number, since it uses less digits than its factorization.

21965428749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23201 (or 23190 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 57.

The spelling of 21965428749 in words is "twenty-one billion, nine hundred sixty-five million, four hundred twenty-eight thousand, seven hundred forty-nine".