21772567 has 2 divisors, whose sum is σ = 21772568. Its totient is φ = 21772566.

The previous prime is 21772561. The next prime is 21772579. The reversal of 21772567 is 76527712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21772567 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21772561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10886283 + 10886284.

It is an arithmetic number, because the mean of its divisors is an integer number (10886284).

Almost surely, 2^21772567 is an apocalyptic number.

21772567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21772567 is an equidigital number, since it uses as much as digits as its factorization.

21772567 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41160, while the sum is 37.

The square root of 21772567 is about 4666.1083356476. The cubic root of 21772567 is about 279.2350164960.

The spelling of 21772567 in words is "twenty-one million, seven hundred seventy-two thousand, five hundred sixty-seven".