21506614 has 4 divisors (see below), whose sum is σ = 32259924. Its totient is φ = 10753306.

The previous prime is 21506609. The next prime is 21506627. The reversal of 21506614 is 41660512.

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, 5376652 + ... + 5376655.

It is an arithmetic number, because the mean of its divisors is an integer number (8064981).

Almost surely, 2^21506614 is an apocalyptic number.

21506614 is a deficient number, since it is larger than the sum of its proper divisors (10753310).

21506614 is a wasteful number, since it uses less digits than its factorization.

21506614 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10753309.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21506614 is about 4637.5223988677. The cubic root of 21506614 is about 278.0933989092.

The spelling of 21506614 in words is "twenty-one million, five hundred six thousand, six hundred fourteen".