21774792 has 64 divisors (see below), whose sum is σ = 59290560. Its totient is φ = 6624000.

The previous prime is 21774787. The next prime is 21774793. The reversal of 21774792 is 29747712.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 21774792.

It is not an unprimeable number, because it can be changed into a prime (21774793) 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, 31167 + ... + 31857.

It is an arithmetic number, because the mean of its divisors is an integer number (926415).

Almost surely, 2^21774792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21774792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29645280).

21774792 is an abundant number, since it is smaller than the sum of its proper divisors (37515768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21774792 is a wasteful number, since it uses less digits than its factorization.

21774792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 810 counting only the distinct ones).

The product of its digits is 49392, while the sum is 39.

The square root of 21774792 is about 4666.3467509391. The cubic root of 21774792 is about 279.2445281099.

The spelling of 21774792 in words is "twenty-one million, seven hundred seventy-four thousand, seven hundred ninety-two".