21356773161 has 16 divisors (see below), whose sum is σ = 28565913600. Its totient is φ = 14192795408.

The previous prime is 21356773147. The next prime is 21356773183. The reversal of 21356773161 is 16137765312.

It is a cyclic number.

It is not a de Polignac number, because 21356773161 - 2¹³ = 21356764969 is a prime.

It is a super-2 number, since 2×21356773161² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21356773111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1802920 + ... + 1814726.

It is an arithmetic number, because the mean of its divisors is an integer number (1785369600).

Almost surely, 2^21356773161 is an apocalyptic number.

It is an amenable number.

21356773161 is a deficient number, since it is larger than the sum of its proper divisors (7209140439).

21356773161 is a wasteful number, since it uses less digits than its factorization.

21356773161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13668.

The product of its digits is 158760, while the sum is 42.

The spelling of 21356773161 in words is "twenty-one billion, three hundred fifty-six million, seven hundred seventy-three thousand, one hundred sixty-one".