21020873237 has 24 divisors (see below), whose sum is σ = 26667244800. Its totient is φ = 16421330016.

The previous prime is 21020873221. The next prime is 21020873257. The reversal of 21020873237 is 73237802012.

It is a happy number.

It is not a de Polignac number, because 21020873237 - 2⁴ = 21020873221 is a prime.

It is a super-2 number, since 2×21020873237² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21020873197 and 21020873206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020873257) 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, 158537 + ... + 259182.

It is an arithmetic number, because the mean of its divisors is an integer number (1111135200).

Almost surely, 2^21020873237 is an apocalyptic number.

It is an amenable number.

21020873237 is a deficient number, since it is larger than the sum of its proper divisors (5646371563).

21020873237 is a wasteful number, since it uses less digits than its factorization.

21020873237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417825 (or 417818 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 35.

The spelling of 21020873237 in words is "twenty-one billion, twenty million, eight hundred seventy-three thousand, two hundred thirty-seven".