21429374 has 4 divisors (see below), whose sum is σ = 32144064. Its totient is φ = 10714686.

The previous prime is 21429349. The next prime is 21429377. The reversal of 21429374 is 47392412.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21429374.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21429377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5357342 + ... + 5357345.

It is an arithmetic number, because the mean of its divisors is an integer number (8036016).

Almost surely, 2^21429374 is an apocalyptic number.

21429374 is a deficient number, since it is larger than the sum of its proper divisors (10714690).

21429374 is a wasteful number, since it uses less digits than its factorization.

21429374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10714689.

The product of its digits is 12096, while the sum is 32.

The square root of 21429374 is about 4629.1871856731. The cubic root of 21429374 is about 277.7600797376.

The spelling of 21429374 in words is "twenty-one million, four hundred twenty-nine thousand, three hundred seventy-four".