22020991 has 2 divisors, whose sum is σ = 22020992. Its totient is φ = 22020990.

The previous prime is 22020953. The next prime is 22021007. The reversal of 22020991 is 19902022.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 22020991 - 2¹¹ = 22018943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22020931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11010495 + 11010496.

It is an arithmetic number, because the mean of its divisors is an integer number (11010496).

Almost surely, 2^22020991 is an apocalyptic number.

22020991 is a deficient number, since it is larger than the sum of its proper divisors (1).

22020991 is an equidigital number, since it uses as much as digits as its factorization.

22020991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 22020991 is about 4692.6528744411. The cubic root of 22020991 is about 280.2930223244.

The spelling of 22020991 in words is "twenty-two million, twenty thousand, nine hundred ninety-one".