21204130394 has 4 divisors (see below), whose sum is σ = 31806195594. Its totient is φ = 10602065196.

The previous prime is 21204130393. The next prime is 21204130411. The reversal of 21204130394 is 49303140212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20941852369 + 262278025 = 144713^2 + 16195^2 .

It is not an unprimeable number, because it can be changed into a prime (21204130393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5301032597 + ... + 5301032600.

Almost surely, 2^21204130394 is an apocalyptic number.

21204130394 is a deficient number, since it is larger than the sum of its proper divisors (10602065200).

21204130394 is a wasteful number, since it uses less digits than its factorization.

21204130394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10602065199.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21204130394 in words is "twenty-one billion, two hundred four million, one hundred thirty thousand, three hundred ninety-four".