168821172580 has 12 divisors (see below), whose sum is σ = 354524462460. Its totient is φ = 67528469024.

The previous prime is 168821172491. The next prime is 168821172581. The reversal of 168821172580 is 85271128861.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19050624576 + 149770548004 = 138024^2 + 387002^2 .

It is a super-2 number, since 2×168821172580² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (168821172581) 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, 4220529295 + ... + 4220529334.

It is an arithmetic number, because the mean of its divisors is an integer number (29543705205).

Almost surely, 2^168821172580 is an apocalyptic number.

168821172580 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

168821172580 is an abundant number, since it is smaller than the sum of its proper divisors (185703289880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

168821172580 is a wasteful number, since it uses less digits than its factorization.

168821172580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8441058638 (or 8441058636 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 49.

The spelling of 168821172580 in words is "one hundred sixty-eight billion, eight hundred twenty-one million, one hundred seventy-two thousand, five hundred eighty".