21761190 has 128 divisors (see below), whose sum is σ = 67184640. Its totient is φ = 4953600.

The previous prime is 21761167. The next prime is 21761191. The reversal of 21761190 is 9116712.

It is a super-2 number, since 2×21761190² = 947098780432200, which contains 22 as substring.

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 (21761191) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 50275 + ... + 50705.

It is an arithmetic number, because the mean of its divisors is an integer number (524880).

Almost surely, 2^21761190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21761190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33592320).

21761190 is an abundant number, since it is smaller than the sum of its proper divisors (45423450).

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

21761190 is a wasteful number, since it uses less digits than its factorization.

21761190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 21761190 is about 4664.8890662051. The cubic root of 21761190 is about 279.1863710257.

The spelling of 21761190 in words is "twenty-one million, seven hundred sixty-one thousand, one hundred ninety".