20411987 has 4 divisors (see below), whose sum is σ = 20426640. Its totient is φ = 20397336.

The previous prime is 20411983. The next prime is 20412037. The reversal of 20411987 is 78911402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20411987 - 2² = 20411983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20411983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4988 + ... + 8105.

It is an arithmetic number, because the mean of its divisors is an integer number (5106660).

Almost surely, 2^20411987 is an apocalyptic number.

20411987 is a deficient number, since it is larger than the sum of its proper divisors (14653).

20411987 is a wasteful number, since it uses less digits than its factorization.

20411987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14652.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 20411987 is about 4517.9627045827. The cubic root of 20411987 is about 273.2929494505.

The spelling of 20411987 in words is "twenty million, four hundred eleven thousand, nine hundred eighty-seven".