21505611414400 has 48 divisors (see below), whose sum is σ = 53125580705040. Its totient is φ = 8602244564480.

The previous prime is 21505611414379. The next prime is 21505611414403. The reversal of 21505611414400 is 441411650512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21505611414403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3360248584 + ... + 3360254983.

It is an arithmetic number, because the mean of its divisors is an integer number (1106782931355).

Almost surely, 2^{21505611414400} is an apocalyptic number.

21505611414400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21505611414400 is an abundant number, since it is smaller than the sum of its proper divisors (31619969290640).

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

21505611414400 is an equidigital number, since it uses as much as digits as its factorization.

21505611414400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6720503591 (or 6720503574 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The spelling of 21505611414400 in words is "twenty-one trillion, five hundred five billion, six hundred eleven million, four hundred fourteen thousand, four hundred".