163457665921 has 12 divisors (see below), whose sum is σ = 181258344036. Its totient is φ = 147282840320.

The previous prime is 163457665907. The next prime is 163457666017. The reversal of 163457665921 is 129566754361.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 45066619521 + 118391046400 = 212289^2 + 344080^2 .

It is not a de Polignac number, because 163457665921 - 2⁷ = 163457665793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (163457665901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5963716 + ... + 5991061.

It is an arithmetic number, because the mean of its divisors is an integer number (15104862003).

Almost surely, 2^163457665921 is an apocalyptic number.

163457665921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

163457665921 is a deficient number, since it is larger than the sum of its proper divisors (17800678115).

163457665921 is a wasteful number, since it uses less digits than its factorization.

163457665921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11954912 (or 11954901 counting only the distinct ones).

The product of its digits is 8164800, while the sum is 55.

The spelling of 163457665921 in words is "one hundred sixty-three billion, four hundred fifty-seven million, six hundred sixty-five thousand, nine hundred twenty-one".