21699229 has 2 divisors, whose sum is σ = 21699230. Its totient is φ = 21699228.

The previous prime is 21699211. The next prime is 21699247. The reversal of 21699229 is 92299612.

It is a balanced prime because it is at equal distance from previous prime (21699211) and next prime (21699247).

It can be written as a sum of positive squares in only one way, i.e., 21622500 + 76729 = 4650^2 + 277^2 .

It is a cyclic number.

It is not a de Polignac number, because 21699229 - 2¹³ = 21691037 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21699191 and 21699200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21699269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10849614 + 10849615.

It is an arithmetic number, because the mean of its divisors is an integer number (10849615).

Almost surely, 2^21699229 is an apocalyptic number.

It is an amenable number.

21699229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21699229 is an equidigital number, since it uses as much as digits as its factorization.

21699229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 40.

The square root of 21699229 is about 4658.2431237538. The cubic root of 21699229 is about 278.9211417955.

The spelling of 21699229 in words is "twenty-one million, six hundred ninety-nine thousand, two hundred twenty-nine".