20610987 has 16 divisors (see below), whose sum is σ = 29810592. Its totient is φ = 12615680.

The previous prime is 20610983. The next prime is 20611007. The reversal of 20610987 is 78901602.

It is a cyclic number.

It is not a de Polignac number, because 20610987 - 2² = 20610983 is a prime.

It is a super-2 number, since 2×20610987² = 849625570228338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20610983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2838 + ... + 7019.

It is an arithmetic number, because the mean of its divisors is an integer number (1863162).

Almost surely, 2^20610987 is an apocalyptic number.

20610987 is a deficient number, since it is larger than the sum of its proper divisors (9199605).

20610987 is a wasteful number, since it uses less digits than its factorization.

20610987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9918.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 20610987 is about 4539.9324884848. The cubic root of 20610987 is about 274.1782055956.

The spelling of 20610987 in words is "twenty million, six hundred ten thousand, nine hundred eighty-seven".