172122621840 has 800 divisors, whose sum is σ = 699738547200. Its totient is φ = 38832721920.

The previous prime is 172122621833. The next prime is 172122621841. The reversal of 172122621840 is 48126221271.

172122621840 is a `hidden beast` number, since 1 + 7 + 2 + 1 + 22 + 621 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 172122621795 and 172122621804.

It is not an unprimeable number, because it can be changed into a prime (172122621841) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 49615626 + ... + 49619094.

It is an arithmetic number, because the mean of its divisors is an integer number (874673184).

Almost surely, 2^172122621840 is an apocalyptic number.

172122621840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172122621840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349869273600).

172122621840 is an abundant number, since it is smaller than the sum of its proper divisors (527615925360).

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

172122621840 is a wasteful number, since it uses less digits than its factorization.

172122621840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3557 (or 3542 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 172122621840 in words is "one hundred seventy-two billion, one hundred twenty-two million, six hundred twenty-one thousand, eight hundred forty".