21683371 has 2 divisors, whose sum is σ = 21683372. Its totient is φ = 21683370.

The previous prime is 21683359. The next prime is 21683377. The reversal of 21683371 is 17338612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21683371 - 2⁵ = 21683339 is a prime.

It is not a weakly prime, because it can be changed into another prime (21683377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10841685 + 10841686.

It is an arithmetic number, because the mean of its divisors is an integer number (10841686).

Almost surely, 2^21683371 is an apocalyptic number.

21683371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21683371 is an equidigital number, since it uses as much as digits as its factorization.

21683371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 21683371 is about 4656.5406687798. The cubic root of 21683371 is about 278.8531791751.

The spelling of 21683371 in words is "twenty-one million, six hundred eighty-three thousand, three hundred seventy-one".