21537051369 has 8 divisors (see below), whose sum is σ = 28733405280. Its totient is φ = 14349365856.

The previous prime is 21537051331. The next prime is 21537051407. The reversal of 21537051369 is 96315073512.

It is an interprime number because it is at equal distance from previous prime (21537051331) and next prime (21537051407).

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

It is not a de Polignac number, because 21537051369 - 2⁷ = 21537051241 is a prime.

It is a super-2 number, since 2×21537051369² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21537051369.

It is not an unprimeable number, because it can be changed into a prime (21537051169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2161299 + ... + 2171240.

It is an arithmetic number, because the mean of its divisors is an integer number (3591675660).

Almost surely, 2^21537051369 is an apocalyptic number.

It is an amenable number.

21537051369 is a deficient number, since it is larger than the sum of its proper divisors (7196353911).

21537051369 is a wasteful number, since it uses less digits than its factorization.

21537051369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4334199.

The product of its (nonzero) digits is 170100, while the sum is 42.

The spelling of 21537051369 in words is "twenty-one billion, five hundred thirty-seven million, fifty-one thousand, three hundred sixty-nine".