21430994 has 8 divisors (see below), whose sum is σ = 34619340. Its totient is φ = 9891216.

The previous prime is 21430991. The next prime is 21431017. The reversal of 21430994 is 49903412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21114025 + 316969 = 4595^2 + 563^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21430994.

It is not an unprimeable number, because it can be changed into a prime (21430991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412109 + ... + 412160.

Almost surely, 2^21430994 is an apocalyptic number.

21430994 is a deficient number, since it is larger than the sum of its proper divisors (13188346).

21430994 is a wasteful number, since it uses less digits than its factorization.

21430994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824284.

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

The square root of 21430994 is about 4629.3621590884. The cubic root of 21430994 is about 277.7670788531.

The spelling of 21430994 in words is "twenty-one million, four hundred thirty thousand, nine hundred ninety-four".