21772799 has 4 divisors (see below), whose sum is σ = 21843120. Its totient is φ = 21702480.

The previous prime is 21772787. The next prime is 21772811. The reversal of 21772799 is 99727712.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21772787) and next prime (21772811).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21772799 is a prime.

It is a Duffinian number.

21772799 is a modest number, since divided by 2799 gives 2177 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21772759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34694 + ... + 35315.

It is an arithmetic number, because the mean of its divisors is an integer number (5460780).

Almost surely, 2^21772799 is an apocalyptic number.

21772799 is a deficient number, since it is larger than the sum of its proper divisors (70321).

21772799 is an equidigital number, since it uses as much as digits as its factorization.

21772799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70320.

The product of its digits is 111132, while the sum is 44.

The square root of 21772799 is about 4666.1331956986. The cubic root of 21772799 is about 279.2360082991.

The spelling of 21772799 in words is "twenty-one million, seven hundred seventy-two thousand, seven hundred ninety-nine".