21470518 has 4 divisors (see below), whose sum is σ = 32205780. Its totient is φ = 10735258.

The previous prime is 21470509. The next prime is 21470521. The reversal of 21470518 is 81507412.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5367628 + ... + 5367631.

It is an arithmetic number, because the mean of its divisors is an integer number (8051445).

Almost surely, 2^21470518 is an apocalyptic number.

21470518 is a deficient number, since it is larger than the sum of its proper divisors (10735262).

21470518 is a wasteful number, since it uses less digits than its factorization.

21470518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10735261.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21470518 is about 4633.6290313317. The cubic root of 21470518 is about 277.9377308216.

The spelling of 21470518 in words is "twenty-one million, four hundred seventy thousand, five hundred eighteen".