21887339 has 2 divisors, whose sum is σ = 21887340. Its totient is φ = 21887338.

The previous prime is 21887293. The next prime is 21887351. The reversal of 21887339 is 93378812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21887339 - 2²⁴ = 5110123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21887296 and 21887305.

It is not a weakly prime, because it can be changed into another prime (21887389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10943669 + 10943670.

It is an arithmetic number, because the mean of its divisors is an integer number (10943670).

Almost surely, 2^21887339 is an apocalyptic number.

21887339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21887339 is an equidigital number, since it uses as much as digits as its factorization.

21887339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 21887339 is about 4678.3906420905. The cubic root of 21887339 is about 279.7248104091.

The spelling of 21887339 in words is "twenty-one million, eight hundred eighty-seven thousand, three hundred thirty-nine".