21161350783 has 4 divisors (see below), whose sum is σ = 21348619488. Its totient is φ = 20974082080.

The previous prime is 21161350751. The next prime is 21161350801. The reversal of 21161350783 is 38705316112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21161350783 - 2⁵ = 21161350751 is a prime.

It is a super-2 number, since 2×21161350783² (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 (21161350183) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93634183 + ... + 93634408.

It is an arithmetic number, because the mean of its divisors is an integer number (5337154872).

Almost surely, 2^21161350783 is an apocalyptic number.

21161350783 is a deficient number, since it is larger than the sum of its proper divisors (187268705).

21161350783 is a wasteful number, since it uses less digits than its factorization.

21161350783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187268704.

The product of its (nonzero) digits is 30240, while the sum is 37.

Adding to 21161350783 its reverse (38705316112), we get a palindrome (59866666895).

The spelling of 21161350783 in words is "twenty-one billion, one hundred sixty-one million, three hundred fifty thousand, seven hundred eighty-three".