21206905298 has 4 divisors (see below), whose sum is σ = 31810357950. Its totient is φ = 10603452648.

The previous prime is 21206905277. The next prime is 21206905301. The reversal of 21206905298 is 89250960212.

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., 15273746569 + 5933158729 = 123587^2 + 77027^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5301726323 + ... + 5301726326.

Almost surely, 2^21206905298 is an apocalyptic number.

21206905298 is a deficient number, since it is larger than the sum of its proper divisors (10603452652).

21206905298 is a wasteful number, since it uses less digits than its factorization.

21206905298 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10603452651.

The product of its (nonzero) digits is 155520, while the sum is 44.

The spelling of 21206905298 in words is "twenty-one billion, two hundred six million, nine hundred five thousand, two hundred ninety-eight".