21722680 has 48 divisors (see below), whose sum is σ = 56860920. Its totient is φ = 7447104.

The previous prime is 21722671. The next prime is 21722689. The reversal of 21722680 is 8622712.

It is an interprime number because it is at equal distance from previous prime (21722671) and next prime (21722689).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722689) 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 11 ways as a sum of consecutive naturals, for example, 3582 + ... + 7501.

Almost surely, 2^21722680 is an apocalyptic number.

21722680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21722680 is an abundant number, since it is smaller than the sum of its proper divisors (35138240).

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

21722680 is a wasteful number, since it uses less digits than its factorization.

21722680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11108 (or 11097 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21722680 is about 4660.7595947442. The cubic root of 21722680 is about 279.0215850688.

The spelling of 21722680 in words is "twenty-one million, seven hundred twenty-two thousand, six hundred eighty".