21433730 has 32 divisors (see below), whose sum is σ = 40407984. Its totient is φ = 8176896.

The previous prime is 21433703. The next prime is 21433733. The reversal of 21433730 is 3733412.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 20729809 + 703921 = 4553^2 + 839^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21433696 and 21433705.

It is not an unprimeable number, because it can be changed into a prime (21433733) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19064 + ... + 20156.

Almost surely, 2^21433730 is an apocalyptic number.

21433730 is a deficient number, since it is larger than the sum of its proper divisors (18974254).

21433730 is a wasteful number, since it uses less digits than its factorization.

21433730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1190.

The product of its (nonzero) digits is 1512, while the sum is 23.

The square root of 21433730 is about 4629.6576547300. The cubic root of 21433730 is about 277.7788987807.

The spelling of 21433730 in words is "twenty-one million, four hundred thirty-three thousand, seven hundred thirty".