21656514 has 16 divisors (see below), whose sum is σ = 47250720. Its totient is φ = 6562560.

The previous prime is 21656513. The next prime is 21656539. The reversal of 21656514 is 41565612.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21656513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163999 + ... + 164130.

It is an arithmetic number, because the mean of its divisors is an integer number (2953170).

Almost surely, 2^21656514 is an apocalyptic number.

21656514 is an abundant number, since it is smaller than the sum of its proper divisors (25594206).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21656514 is a wasteful number, since it uses less digits than its factorization.

21656514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328145.

The product of its digits is 7200, while the sum is 30.

The square root of 21656514 is about 4653.6559821285. The cubic root of 21656514 is about 278.7380025268.

The spelling of 21656514 in words is "twenty-one million, six hundred fifty-six thousand, five hundred fourteen".