21670339 has 2 divisors, whose sum is σ = 21670340. Its totient is φ = 21670338.

The previous prime is 21670331. The next prime is 21670373. The reversal of 21670339 is 93307612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21670339 - 2³ = 21670331 is a prime.

It is equal to p_1369660 and since 21670339 and 1369660 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21670339.

It is not a weakly prime, because it can be changed into another prime (21670331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10835169 + 10835170.

It is an arithmetic number, because the mean of its divisors is an integer number (10835170).

Almost surely, 2^21670339 is an apocalyptic number.

21670339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21670339 is an equidigital number, since it uses as much as digits as its factorization.

21670339 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 21670339 is about 4655.1411364211. The cubic root of 21670339 is about 278.7973031322.

The spelling of 21670339 in words is "twenty-one million, six hundred seventy thousand, three hundred thirty-nine".