21423074 has 32 divisors (see below), whose sum is σ = 35392896. Its totient is φ = 9694080.

The previous prime is 21423067. The next prime is 21423079. The reversal of 21423074 is 47032412.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (21423079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69629 + ... + 69935.

It is an arithmetic number, because the mean of its divisors is an integer number (1106028).

Almost surely, 2^21423074 is an apocalyptic number.

21423074 is a deficient number, since it is larger than the sum of its proper divisors (13969822).

21423074 is a wasteful number, since it uses less digits than its factorization.

21423074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21423074 is about 4628.5066706228. The cubic root of 21423074 is about 277.7328576014.

Adding to 21423074 its reverse (47032412), we get a palindrome (68455486).

The spelling of 21423074 in words is "twenty-one million, four hundred twenty-three thousand, seventy-four".