21890093 has 2 divisors, whose sum is σ = 21890094. Its totient is φ = 21890092.

The previous prime is 21890083. The next prime is 21890107. The reversal of 21890093 is 39009812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16024009 + 5866084 = 4003^2 + 2422^2 .

It is a cyclic number.

It is not a de Polignac number, because 21890093 - 2²² = 17695789 is a prime.

It is a Chen prime.

It is equal to p_1382738 and since 21890093 and 1382738 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21890083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10945046 + 10945047.

It is an arithmetic number, because the mean of its divisors is an integer number (10945047).

Almost surely, 2^21890093 is an apocalyptic number.

It is an amenable number.

21890093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21890093 is an equidigital number, since it uses as much as digits as its factorization.

21890093 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21890093 is about 4678.6849648165. The cubic root of 21890093 is about 279.7365421507.

The spelling of 21890093 in words is "twenty-one million, eight hundred ninety thousand, ninety-three".