21097422 has 40 divisors (see below), whose sum is σ = 48810432. Its totient is φ = 6804000.

The previous prime is 21097421. The next prime is 21097423. The reversal of 21097422 is 22479012.

It is an interprime number because it is at equal distance from previous prime (21097421) and next prime (21097423).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21097421) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2922 + ... + 7122.

Almost surely, 2^21097422 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21097422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24405216).

21097422 is an abundant number, since it is smaller than the sum of its proper divisors (27713010).

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

21097422 is a wasteful number, since it uses less digits than its factorization.

21097422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4246 (or 4237 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21097422 is about 4593.1930070486. The cubic root of 21097422 is about 276.3183943729.

The spelling of 21097422 in words is "twenty-one million, ninety-seven thousand, four hundred twenty-two".