21622655 has 8 divisors (see below), whose sum is σ = 26784384. Its totient is φ = 16740000.

The previous prime is 21622651. The next prime is 21622681. The reversal of 21622655 is 55622612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21622655 - 2² = 21622651 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21622651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69596 + ... + 69905.

It is an arithmetic number, because the mean of its divisors is an integer number (3348048).

Almost surely, 2^21622655 is an apocalyptic number.

21622655 is a deficient number, since it is larger than the sum of its proper divisors (5161729).

21622655 is a wasteful number, since it uses less digits than its factorization.

21622655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139537.

The product of its digits is 7200, while the sum is 29.

The square root of 21622655 is about 4650.0166666368. The cubic root of 21622655 is about 278.5926619174.

The spelling of 21622655 in words is "twenty-one million, six hundred twenty-two thousand, six hundred fifty-five".