21682970 has 8 divisors (see below), whose sum is σ = 39029364. Its totient is φ = 8673184.

The previous prime is 21682967. The next prime is 21682979. The reversal of 21682970 is 7928612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19775809 + 1907161 = 4447^2 + 1381^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21682970.

It is not an unprimeable number, because it can be changed into a prime (21682979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084139 + ... + 1084158.

Almost surely, 2^21682970 is an apocalyptic number.

21682970 is a deficient number, since it is larger than the sum of its proper divisors (17346394).

21682970 is a wasteful number, since it uses less digits than its factorization.

21682970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168304.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 21682970 is about 4656.4976108659. The cubic root of 21682970 is about 278.8514601801.

The spelling of 21682970 in words is "twenty-one million, six hundred eighty-two thousand, nine hundred seventy".