21489898 has 4 divisors (see below), whose sum is σ = 32234850. Its totient is φ = 10744948.

The previous prime is 21489883. The next prime is 21489901. The reversal of 21489898 is 89898412.

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., 13155129 + 8334769 = 3627^2 + 2887^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5372473 + ... + 5372476.

Almost surely, 2^21489898 is an apocalyptic number.

21489898 is a deficient number, since it is larger than the sum of its proper divisors (10744952).

21489898 is a wasteful number, since it uses less digits than its factorization.

21489898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10744951.

The product of its digits is 331776, while the sum is 49.

The square root of 21489898 is about 4635.7197930850. The cubic root of 21489898 is about 278.0213309375.

The spelling of 21489898 in words is "twenty-one million, four hundred eighty-nine thousand, eight hundred ninety-eight".