21160666464 has 288 divisors, whose sum is σ = 67211569152. Its totient is φ = 5812128000.

The previous prime is 21160666427. The next prime is 21160666493. The reversal of 21160666464 is 46466606112.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 140136789 + ... + 140136939.

It is an arithmetic number, because the mean of its divisors is an integer number (233373504).

Almost surely, 2^21160666464 is an apocalyptic number.

21160666464 is a gapful number since it is divisible by the number (24) 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 21160666464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33605784576).

21160666464 is an abundant number, since it is smaller than the sum of its proper divisors (46050902688).

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

21160666464 is an equidigital number, since it uses as much as digits as its factorization.

21160666464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 42.

The spelling of 21160666464 in words is "twenty-one billion, one hundred sixty million, six hundred sixty-six thousand, four hundred sixty-four".