21690185340537 has 12 divisors (see below), whose sum is σ = 35806020244800. Its totient is φ = 12394391623128.

The previous prime is 21690185340533. The next prime is 21690185340589. The reversal of 21690185340537 is 73504358109612.

It is a happy number.

21690185340537 is a `hidden beast` number, since 2 + 1 + 6 + 9 + 0 + 18 + 53 + 40 + 537 = 666.

It is not a de Polignac number, because 21690185340537 - 2² = 21690185340533 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21690185340533) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172144328037 + ... + 172144328162.

It is an arithmetic number, because the mean of its divisors is an integer number (2983835020400).

It is a 1-persistent number, because it is pandigital, but 2⋅21690185340537 = 43380370681074 is not.

Almost surely, 2^{21690185340537} is an apocalyptic number.

It is an amenable number.

21690185340537 is a deficient number, since it is larger than the sum of its proper divisors (14115834904263).

21690185340537 is a wasteful number, since it uses less digits than its factorization.

21690185340537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344288656212 (or 344288656209 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 54.

The spelling of 21690185340537 in words is "twenty-one trillion, six hundred ninety billion, one hundred eighty-five million, three hundred forty thousand, five hundred thirty-seven".