21217467627972 has 864 divisors, whose sum is σ = 71545035161600. Its totient is φ = 5289794294400.

The previous prime is 21217467627949. The next prime is 21217467627973. The reversal of 21217467627972 is 27972676471212.

It is a happy number.

21217467627972 is a `hidden beast` number, since 2 + 1 + 21 + 7 + 467 + 62 + 7 + 97 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21217467627973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 5882301393 + ... + 5882304999.

Almost surely, 2^{21217467627972} is an apocalyptic number.

21217467627972 is a gapful number since it is divisible by the number (22) 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 21217467627972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35772517580800).

21217467627972 is an abundant number, since it is smaller than the sum of its proper divisors (50327567533628).

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

21217467627972 is a wasteful number, since it uses less digits than its factorization.

21217467627972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3818 (or 3788 counting only the distinct ones).

The product of its digits is 49787136, while the sum is 63.

The spelling of 21217467627972 in words is "twenty-one trillion, two hundred seventeen billion, four hundred sixty-seven million, six hundred twenty-seven thousand, nine hundred seventy-two".