21629445 has 8 divisors (see below), whose sum is σ = 34607136. Its totient is φ = 11535696.

The previous prime is 21629437. The next prime is 21629471. The reversal of 21629445 is 54492612.

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

It is not a de Polignac number, because 21629445 - 2³ = 21629437 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 720967 + ... + 720996.

It is an arithmetic number, because the mean of its divisors is an integer number (4325892).

Almost surely, 2^21629445 is an apocalyptic number.

It is an amenable number.

21629445 is a deficient number, since it is larger than the sum of its proper divisors (12977691).

21629445 is a wasteful number, since it uses less digits than its factorization.

21629445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1441971.

The product of its digits is 17280, while the sum is 33.

The square root of 21629445 is about 4650.7467142385. The cubic root of 21629445 is about 278.6218203194.

The spelling of 21629445 in words is "twenty-one million, six hundred twenty-nine thousand, four hundred forty-five".