21980190 has 16 divisors (see below), whose sum is σ = 52752528. Its totient is φ = 5861376.

The previous prime is 21980171. The next prime is 21980197. The reversal of 21980190 is 9108912.

It is a super-2 number, since 2×21980190² = 966257504872200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 732673 = 21980190 / (2 + 1 + 9 + 8 + 0 + 1 + 9 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 366307 + ... + 366366.

It is an arithmetic number, because the mean of its divisors is an integer number (3297033).

Almost surely, 2^21980190 is an apocalyptic number.

21980190 is an abundant number, since it is smaller than the sum of its proper divisors (30772338).

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

21980190 is a wasteful number, since it uses less digits than its factorization.

21980190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732683.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 21980190 is about 4688.3035311294. The cubic root of 21980190 is about 280.1198041740.

The spelling of 21980190 in words is "twenty-one million, nine hundred eighty thousand, one hundred ninety".