21853660946 has 16 divisors (see below), whose sum is σ = 35312495064. Its totient is φ = 10083325824.

The previous prime is 21853660921. The next prime is 21853660967. The reversal of 21853660946 is 64906635812.

It can be written as a sum of positive squares in 4 ways, for example, as 9278505625 + 12575155321 = 96325^2 + 112139^2 .

It is a super-2 number, since 2×21853660946² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21853660894 and 21853660903.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33161 + ... + 211676.

Almost surely, 2^21853660946 is an apocalyptic number.

21853660946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21853660946 is a deficient number, since it is larger than the sum of its proper divisors (13458834118).

21853660946 is a wasteful number, since it uses less digits than its factorization.

21853660946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248285.

The product of its (nonzero) digits is 1866240, while the sum is 50.

The spelling of 21853660946 in words is "twenty-one billion, eight hundred fifty-three million, six hundred sixty thousand, nine hundred forty-six".