21111718373001 has 27 divisors (see below), whose sum is σ = 30544462233831. Its totient is φ = 14051551117824.

The previous prime is 21111718372993. The next prime is 21111718373023. The reversal of 21111718373001 is 10037381711112.

It is a happy number.

The square root of 21111718373001 is 4594749.

It is a perfect power (a square), and thus also a powerful number.

21111718373001 is a `hidden beast` number, since 2 + 111 + 171 + 8 + 373 + 0 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 268841213001 + 20842877160000 = 518499^2 + 4565400^2 .

It is not a de Polignac number, because 21111718373001 - 2³ = 21111718372993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21111718373051) 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 26 ways as a sum of consecutive naturals, for example, 14983475785 + ... + 14983477193.

Almost surely, 2^{21111718373001} is an apocalyptic number.

21111718373001 is the 4594749-th square number.

21111718373001 is the 2297375-th centered octagonal number.

It is an amenable number.

21111718373001 is a deficient number, since it is larger than the sum of its proper divisors (9432743860830).

21111718373001 is an frugal number, since it uses more digits than its factorization.

21111718373001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4998 (or 2499 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 36.

Multiplying 21111718373001 by its sum of digits (36), we get a square (760021861428036 = 27568494²).

The spelling of 21111718373001 in words is "twenty-one trillion, one hundred eleven billion, seven hundred eighteen million, three hundred seventy-three thousand, one".