21740886 has 40 divisors (see below), whose sum is σ = 49864584. Its totient is φ = 7076160.

The previous prime is 21740869. The next prime is 21740903. The reversal of 21740886 is 68804712.

It is an interprime number because it is at equal distance from previous prime (21740869) and next prime (21740903).

It is a super-2 number, since 2×21740886² = 945332248129992, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21740886.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5406 + ... + 8526.

Almost surely, 2^21740886 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21740886, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24932292).

21740886 is an abundant number, since it is smaller than the sum of its proper divisors (28123698).

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

21740886 is a wasteful number, since it uses less digits than its factorization.

21740886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3178 (or 3169 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21740886 is about 4662.7123007966. The cubic root of 21740886 is about 279.0995135821.

The spelling of 21740886 in words is "twenty-one million, seven hundred forty thousand, eight hundred eighty-six".