21522755 has 8 divisors (see below), whose sum is σ = 25912224. Its totient is φ = 17161600.

The previous prime is 21522749. The next prime is 21522791. The reversal of 21522755 is 55722512.

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

It is not a de Polignac number, because 21522755 - 2²⁴ = 4745539 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5366 + ... + 8475.

It is an arithmetic number, because the mean of its divisors is an integer number (3239028).

Almost surely, 2^21522755 is an apocalyptic number.

21522755 is a deficient number, since it is larger than the sum of its proper divisors (4389469).

21522755 is a wasteful number, since it uses less digits than its factorization.

21522755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14157.

The product of its digits is 7000, while the sum is 29.

The square root of 21522755 is about 4639.2623336043. The cubic root of 21522755 is about 278.1629524440.

The spelling of 21522755 in words is "twenty-one million, five hundred twenty-two thousand, seven hundred fifty-five".