21429694 has 16 divisors (see below), whose sum is σ = 37764720. Its totient is φ = 8991360.

The previous prime is 21429691. The next prime is 21429703. The reversal of 21429694 is 49692412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21429691) 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 7 ways as a sum of consecutive naturals, for example, 37179 + ... + 37750.

It is an arithmetic number, because the mean of its divisors is an integer number (2360295).

Almost surely, 2^21429694 is an apocalyptic number.

21429694 is a deficient number, since it is larger than the sum of its proper divisors (16335026).

21429694 is a wasteful number, since it uses less digits than its factorization.

21429694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74955.

The product of its digits is 31104, while the sum is 37.

The square root of 21429694 is about 4629.2217488472. The cubic root of 21429694 is about 277.7614623069.

The spelling of 21429694 in words is "twenty-one million, four hundred twenty-nine thousand, six hundred ninety-four".