21426583 has 2 divisors, whose sum is σ = 21426584. Its totient is φ = 21426582.

The previous prime is 21426553. The next prime is 21426607. The reversal of 21426583 is 38562412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21426583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21426553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10713291 + 10713292.

It is an arithmetic number, because the mean of its divisors is an integer number (10713292).

Almost surely, 2^21426583 is an apocalyptic number.

21426583 is a deficient number, since it is larger than the sum of its proper divisors (1).

21426583 is an equidigital number, since it uses as much as digits as its factorization.

21426583 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 31.

The square root of 21426583 is about 4628.8857190473. The cubic root of 21426583 is about 277.7480205575.

Adding to 21426583 its reverse (38562412), we get a palindrome (59988995).

The spelling of 21426583 in words is "twenty-one million, four hundred twenty-six thousand, five hundred eighty-three".