21661514 has 8 divisors (see below), whose sum is σ = 37134048. Its totient is φ = 9283500.

The previous prime is 21661499. The next prime is 21661517. The reversal of 21661514 is 41516612.

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

It is not an unprimeable number, because it can be changed into a prime (21661517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 773612 + ... + 773639.

It is an arithmetic number, because the mean of its divisors is an integer number (4641756).

Almost surely, 2^21661514 is an apocalyptic number.

21661514 is a deficient number, since it is larger than the sum of its proper divisors (15472534).

21661514 is a wasteful number, since it uses less digits than its factorization.

21661514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547260.

The product of its digits is 1440, while the sum is 26.

The square root of 21661514 is about 4654.1931631594. The cubic root of 21661514 is about 278.7594523127.

The spelling of 21661514 in words is "twenty-one million, six hundred sixty-one thousand, five hundred fourteen".