21434990 has 16 divisors (see below), whose sum is σ = 39112848. Its totient is φ = 8456256.

The previous prime is 21434957. The next prime is 21435017. The reversal of 21434990 is 9943412.

It is a happy number.

It is a congruent number.

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, 13952 + ... + 15411.

It is an arithmetic number, because the mean of its divisors is an integer number (2444553).

Almost surely, 2^21434990 is an apocalyptic number.

21434990 is a deficient number, since it is larger than the sum of its proper divisors (17677858).

21434990 is a wasteful number, since it uses less digits than its factorization.

21434990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29443.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21434990 is about 4629.7937319064. The cubic root of 21434990 is about 277.7843418301.

The spelling of 21434990 in words is "twenty-one million, four hundred thirty-four thousand, nine hundred ninety".