21512098 has 4 divisors (see below), whose sum is σ = 32268150. Its totient is φ = 10756048.

The previous prime is 21512093. The next prime is 21512129. The reversal of 21512098 is 89021512.

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., 20403289 + 1108809 = 4517^2 + 1053^2 .

It is not an unprimeable number, because it can be changed into a prime (21512093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5378023 + ... + 5378026.

Almost surely, 2^21512098 is an apocalyptic number.

21512098 is a deficient number, since it is larger than the sum of its proper divisors (10756052).

21512098 is a wasteful number, since it uses less digits than its factorization.

21512098 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10756051.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21512098 is about 4638.1136251713. The cubic root of 21512098 is about 278.1170340352.

The spelling of 21512098 in words is "twenty-one million, five hundred twelve thousand, ninety-eight".