22857421 has 2 divisors, whose sum is σ = 22857422. Its totient is φ = 22857420.

The previous prime is 22857407. The next prime is 22857511. The reversal of 22857421 is 12475822.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11634921 + 11222500 = 3411^2 + 3350^2 .

It is a cyclic number.

It is not a de Polignac number, because 22857421 - 2⁵ = 22857389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22857221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11428710 + 11428711.

It is an arithmetic number, because the mean of its divisors is an integer number (11428711).

Almost surely, 2^22857421 is an apocalyptic number.

It is an amenable number.

22857421 is a deficient number, since it is larger than the sum of its proper divisors (1).

22857421 is an equidigital number, since it uses as much as digits as its factorization.

22857421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8960, while the sum is 31.

The square root of 22857421 is about 4780.9435261254. The cubic root of 22857421 is about 283.7978335397.

The spelling of 22857421 in words is "twenty-two million, eight hundred fifty-seven thousand, four hundred twenty-one".