21357615773 has 8 divisors (see below), whose sum is σ = 23050845048. Its totient is φ = 19671577344.

The previous prime is 21357615743. The next prime is 21357615809. The reversal of 21357615773 is 37751675312.

It can be written as a sum of positive squares in 4 ways, for example, as 7878870169 + 13478745604 = 88763^2 + 116098^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21357615773 - 2¹⁶ = 21357550237 is a prime.

It is a super-2 number, since 2×21357615773² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357615743) 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, 1791536 + ... + 1803417.

It is an arithmetic number, because the mean of its divisors is an integer number (2881355631).

Almost surely, 2^21357615773 is an apocalyptic number.

It is an amenable number.

21357615773 is a deficient number, since it is larger than the sum of its proper divisors (1693229275).

21357615773 is a wasteful number, since it uses less digits than its factorization.

21357615773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3595423.

The product of its digits is 926100, while the sum is 47.

The spelling of 21357615773 in words is "twenty-one billion, three hundred fifty-seven million, six hundred fifteen thousand, seven hundred seventy-three".