21580970 has 8 divisors (see below), whose sum is σ = 38845764. Its totient is φ = 8632384.

The previous prime is 21580967. The next prime is 21581003. The reversal of 21580970 is 7908512.

It can be written as a sum of positive squares in 2 ways, for example, as 21464689 + 116281 = 4633^2 + 341^2 .

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

It is a super-2 number, since 2×21580970² = 931476532281800, which contains 22 as substring.

It is an unprimeable number.

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, 1079039 + ... + 1079058.

Almost surely, 2^21580970 is an apocalyptic number.

21580970 is a deficient number, since it is larger than the sum of its proper divisors (17264794).

21580970 is a wasteful number, since it uses less digits than its factorization.

21580970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2158104.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 21580970 is about 4645.5322622924. The cubic root of 21580970 is about 278.4135194722.

The spelling of 21580970 in words is "twenty-one million, five hundred eighty thousand, nine hundred seventy".