20987043 has 24 divisors (see below), whose sum is σ = 35513280. Its totient is φ = 10901520.

The previous prime is 20987041. The next prime is 20987059. The reversal of 20987043 is 34078902.

It is not a de Polignac number, because 20987043 - 2¹ = 20987041 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 20986995 and 20987013.

It is not an unprimeable number, because it can be changed into a prime (20987041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4873 + ... + 8106.

It is an arithmetic number, because the mean of its divisors is an integer number (1479720).

Almost surely, 2^20987043 is an apocalyptic number.

20987043 is a deficient number, since it is larger than the sum of its proper divisors (14526237).

20987043 is a wasteful number, since it uses less digits than its factorization.

20987043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13007 (or 13000 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20987043 is about 4581.1617522196. The cubic root of 20987043 is about 275.8356640903.

The spelling of 20987043 in words is "twenty million, nine hundred eighty-seven thousand, forty-three".