21690586437 has 8 divisors (see below), whose sum is σ = 31145457504. Its totient is φ = 13348053168.

The previous prime is 21690586403. The next prime is 21690586441. The reversal of 21690586437 is 73468509612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21690586437 - 2²³ = 21682197829 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21690586437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21690586537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 278084403 + ... + 278084480.

It is an arithmetic number, because the mean of its divisors is an integer number (3893182188).

It is a 1-persistent number, because it is pandigital, but 2⋅21690586437 = 43381172874 is not.

Almost surely, 2^21690586437 is an apocalyptic number.

It is an amenable number.

21690586437 is a deficient number, since it is larger than the sum of its proper divisors (9454871067).

21690586437 is a wasteful number, since it uses less digits than its factorization.

21690586437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556168899.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 21690586437 in words is "twenty-one billion, six hundred ninety million, five hundred eighty-six thousand, four hundred thirty-seven".