21770892 has 72 divisors (see below), whose sum is σ = 64668240. Its totient is φ = 6088320.

The previous prime is 21770873. The next prime is 21770893. The reversal of 21770892 is 29807712.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21770893) 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, 3034 + ... + 7262.

It is an arithmetic number, because the mean of its divisors is an integer number (898170).

Almost surely, 2^21770892 is an apocalyptic number.

21770892 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21770892, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32334120).

21770892 is an abundant number, since it is smaller than the sum of its proper divisors (42897348).

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

21770892 is a wasteful number, since it uses less digits than its factorization.

21770892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4263 (or 4258 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 21770892 is about 4665.9288464356. The cubic root of 21770892 is about 279.2278556401.

The spelling of 21770892 in words is "twenty-one million, seven hundred seventy thousand, eight hundred ninety-two".