21012098 has 4 divisors (see below), whose sum is σ = 31518150. Its totient is φ = 10506048.

The previous prime is 21012091. The next prime is 21012127. The reversal of 21012098 is 89021012.

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., 18722929 + 2289169 = 4327^2 + 1513^2 .

It is not an unprimeable number, because it can be changed into a prime (21012091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253023 + ... + 5253026.

Almost surely, 2^21012098 is an apocalyptic number.

21012098 is a deficient number, since it is larger than the sum of its proper divisors (10506052).

21012098 is a wasteful number, since it uses less digits than its factorization.

21012098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506051.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 21012098 is about 4583.8955049172. The cubic root of 21012098 is about 275.9453875702.

The spelling of 21012098 in words is "twenty-one million, twelve thousand, ninety-eight".