21860073 has 6 divisors (see below), whose sum is σ = 31575674. Its totient is φ = 14573376.

The previous prime is 21860063. The next prime is 21860077. The reversal of 21860073 is 37006812.

It can be written as a sum of positive squares in only one way, i.e., 14953689 + 6906384 = 3867^2 + 2628^2 .

It is not a de Polignac number, because 21860073 - 2⁴ = 21860057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21860077) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1214440 + ... + 1214457.

Almost surely, 2^21860073 is an apocalyptic number.

It is an amenable number.

21860073 is a deficient number, since it is larger than the sum of its proper divisors (9715601).

21860073 is a wasteful number, since it uses less digits than its factorization.

21860073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2428903 (or 2428900 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21860073 is about 4675.4756977232. The cubic root of 21860073 is about 279.6086070649.

Adding to 21860073 its reverse (37006812), we get a palindrome (58866885).

The spelling of 21860073 in words is "twenty-one million, eight hundred sixty thousand, seventy-three".