21012434 has 8 divisors (see below), whose sum is σ = 31540428. Its totient is φ = 10498960.

The previous prime is 21012421. The next prime is 21012449. The reversal of 21012434 is 43421012.

It can be written as a sum of positive squares in 2 ways, for example, as 20295025 + 717409 = 4505^2 + 847^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1364 + ... + 6624.

Almost surely, 2^21012434 is an apocalyptic number.

21012434 is a deficient number, since it is larger than the sum of its proper divisors (10527994).

21012434 is a wasteful number, since it uses less digits than its factorization.

21012434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7260.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21012434 is about 4583.9321548208. The cubic root of 21012434 is about 275.9468584237.

Adding to 21012434 its reverse (43421012), we get a palindrome (64433446).

The spelling of 21012434 in words is "twenty-one million, twelve thousand, four hundred thirty-four".