21398629 has 8 divisors (see below), whose sum is σ = 24612608. Its totient is φ = 18223920.

The previous prime is 21398623. The next prime is 21398647. The reversal of 21398629 is 92689312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21398629 - 2³ = 21398621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21398591 and 21398600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21398621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8637 + ... + 10834.

It is an arithmetic number, because the mean of its divisors is an integer number (3076576).

Almost surely, 2^21398629 is an apocalyptic number.

It is an amenable number.

21398629 is a deficient number, since it is larger than the sum of its proper divisors (3213979).

21398629 is a wasteful number, since it uses less digits than its factorization.

21398629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19635.

The product of its digits is 46656, while the sum is 40.

The square root of 21398629 is about 4625.8652163676. The cubic root of 21398629 is about 277.6271808340.

The spelling of 21398629 in words is "twenty-one million, three hundred ninety-eight thousand, six hundred twenty-nine".