21650587123 has 4 divisors (see below), whose sum is σ = 23618822328. Its totient is φ = 19682351920.

The previous prime is 21650587117. The next prime is 21650587151. The reversal of 21650587123 is 32178505612.

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

It is not a de Polignac number, because 21650587123 - 2⁹ = 21650586611 is a prime.

It is a super-2 number, since 2×21650587123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21650587103) 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, 984117586 + ... + 984117607.

It is an arithmetic number, because the mean of its divisors is an integer number (5904705582).

Almost surely, 2^21650587123 is an apocalyptic number.

21650587123 is a deficient number, since it is larger than the sum of its proper divisors (1968235205).

21650587123 is a wasteful number, since it uses less digits than its factorization.

21650587123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1968235204.

The product of its (nonzero) digits is 100800, while the sum is 40.

The spelling of 21650587123 in words is "twenty-one billion, six hundred fifty million, five hundred eighty-seven thousand, one hundred twenty-three".