21229407 has 6 divisors (see below), whose sum is σ = 30664712. Its totient is φ = 14152932.

The previous prime is 21229399. The next prime is 21229409. The reversal of 21229407 is 70492212.

It is not a de Polignac number, because 21229407 - 2³ = 21229399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21229409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179403 + ... + 1179420.

Almost surely, 2^21229407 is an apocalyptic number.

21229407 is a deficient number, since it is larger than the sum of its proper divisors (9435305).

21229407 is a wasteful number, since it uses less digits than its factorization.

21229407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358829 (or 2358826 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21229407 is about 4607.5380627836. The cubic root of 21229407 is about 276.8934108356.

The spelling of 21229407 in words is "twenty-one million, two hundred twenty-nine thousand, four hundred seven".