126921217680 has 320 divisors, whose sum is σ = 448428441600. Its totient is φ = 32980631040.

The previous prime is 126921217613. The next prime is 126921217723. The reversal of 126921217680 is 86712129621.

126921217680 is a `hidden beast` number, since 1 + 269 + 212 + 176 + 8 + 0 = 666.

It is a super-2 number, since 2×126921217680² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 24260665 + ... + 24265895.

It is an arithmetic number, because the mean of its divisors is an integer number (1401338880).

Almost surely, 2^126921217680 is an apocalyptic number.

126921217680 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 126921217680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224214220800).

126921217680 is an abundant number, since it is smaller than the sum of its proper divisors (321507223920).

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

126921217680 is a wasteful number, since it uses less digits than its factorization.

126921217680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5539 (or 5527 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 126921217680 in words is "one hundred twenty-six billion, nine hundred twenty-one million, two hundred seventeen thousand, six hundred eighty".