21996611 has 32 divisors (see below), whose sum is σ = 28600320. Its totient is φ = 16454016.

The previous prime is 21996599. The next prime is 21996613. The reversal of 21996611 is 11669912.

It is a cyclic number.

It is not a de Polignac number, because 21996611 - 2¹⁸ = 21734467 is a prime.

Its product of digits (5832) is a multiple of the sum of its prime divisors (243).

It is not an unprimeable number, because it can be changed into a prime (21996613) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 158180 + ... + 158318.

It is an arithmetic number, because the mean of its divisors is an integer number (893760).

Almost surely, 2^21996611 is an apocalyptic number.

21996611 is a deficient number, since it is larger than the sum of its proper divisors (6603709).

21996611 is a wasteful number, since it uses less digits than its factorization.

21996611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243.

The product of its digits is 5832, while the sum is 35.

The square root of 21996611 is about 4690.0544772955. The cubic root of 21996611 is about 280.1895442793.

It can be divided in two parts, 21996 and 611, that multiplied together give a square (13439556 = 3666²).

The spelling of 21996611 in words is "twenty-one million, nine hundred ninety-six thousand, six hundred eleven".