10821987 has 12 divisors (see below), whose sum is σ = 17052984. Its totient is φ = 6558720.

The previous prime is 10821971. The next prime is 10821989. The reversal of 10821987 is 78912801.

It is not a de Polignac number, because 10821987 - 2⁴ = 10821971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (10821989) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54558 + ... + 54755.

It is an arithmetic number, because the mean of its divisors is an integer number (1421082).

Almost surely, 2^10821987 is an apocalyptic number.

10821987 is a deficient number, since it is larger than the sum of its proper divisors (6230997).

10821987 is a wasteful number, since it uses less digits than its factorization.

10821987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109330 (or 109327 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 10821987 is about 3289.6788597065. The cubic root of 10821987 is about 221.1917897232.

The spelling of 10821987 in words is "ten million, eight hundred twenty-one thousand, nine hundred eighty-seven".