21298478 has 8 divisors (see below), whose sum is σ = 32035872. Its totient is φ = 10619856.

The previous prime is 21298471. The next prime is 21298489. The reversal of 21298478 is 87489212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21298471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13775 + ... + 15242.

It is an arithmetic number, because the mean of its divisors is an integer number (4004484).

Almost surely, 2^21298478 is an apocalyptic number.

21298478 is a deficient number, since it is larger than the sum of its proper divisors (10737394).

21298478 is a wasteful number, since it uses less digits than its factorization.

21298478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29386.

The product of its digits is 64512, while the sum is 41.

The square root of 21298478 is about 4615.0274105361. The cubic root of 21298478 is about 277.1933815391.

The spelling of 21298478 in words is "twenty-one million, two hundred ninety-eight thousand, four hundred seventy-eight".