21960987 has 8 divisors (see below), whose sum is σ = 29475840. Its totient is φ = 14543400.

The previous prime is 21960977. The next prime is 21960997. The reversal of 21960987 is 78906912.

It is an interprime number because it is at equal distance from previous prime (21960977) and next prime (21960997).

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

It is not a de Polignac number, because 21960987 - 2¹⁶ = 21895451 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21960937) 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 7 ways as a sum of consecutive naturals, for example, 23787 + ... + 24692.

It is an arithmetic number, because the mean of its divisors is an integer number (3684480).

Almost surely, 2^21960987 is an apocalyptic number.

21960987 is a deficient number, since it is larger than the sum of its proper divisors (7514853).

21960987 is a wasteful number, since it uses less digits than its factorization.

21960987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48633.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 21960987 is about 4686.2551146945. The cubic root of 21960987 is about 280.0382048209.

The spelling of 21960987 in words is "twenty-one million, nine hundred sixty thousand, nine hundred eighty-seven".