11357217821 has 8 divisors (see below), whose sum is σ = 11795231160. Its totient is φ = 10926102528.

The previous prime is 11357217797. The next prime is 11357217841. The reversal of 11357217821 is 12871275311.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3698342596 + 7658875225 = 60814^2 + 87515^2 .

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 11357217821 - 2¹⁰ = 11357216797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11357217841) 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, 1721156 + ... + 1727741.

It is an arithmetic number, because the mean of its divisors is an integer number (1474403895).

Almost surely, 2^11357217821 is an apocalyptic number.

It is an amenable number.

11357217821 is a deficient number, since it is larger than the sum of its proper divisors (438013339).

11357217821 is an equidigital number, since it uses as much as digits as its factorization.

11357217821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3449023.

The product of its digits is 23520, while the sum is 38.

The spelling of 11357217821 in words is "eleven billion, three hundred fifty-seven million, two hundred seventeen thousand, eight hundred twenty-one".