21812434 has 16 divisors (see below), whose sum is σ = 37487808. Its totient is φ = 9324432.

The previous prime is 21812429. The next prime is 21812447. The reversal of 21812434 is 43421812.

It is a junction number, because it is equal to n+sod(n) for n = 21812399 and 21812408.

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, 4444 + ... + 7960.

It is an arithmetic number, because the mean of its divisors is an integer number (2342988).

Almost surely, 2^21812434 is an apocalyptic number.

21812434 is a deficient number, since it is larger than the sum of its proper divisors (15675374).

21812434 is a wasteful number, since it uses less digits than its factorization.

21812434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3969.

The product of its digits is 1536, while the sum is 25.

The square root of 21812434 is about 4670.3783572640. The cubic root of 21812434 is about 279.4053451283.

The spelling of 21812434 in words is "twenty-one million, eight hundred twelve thousand, four hundred thirty-four".