21500235202645 has 32 divisors (see below), whose sum is σ = 27516123273600. Its totient is φ = 16081394079744.

The previous prime is 21500235202643. The next prime is 21500235202717. The reversal of 21500235202645 is 54620253200512.

It is a cyclic number.

It is not a de Polignac number, because 21500235202645 - 2¹ = 21500235202643 is a prime.

It is a super-2 number, since 2×21500235202645² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500235202643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1796635 + ... + 6799144.

It is an arithmetic number, because the mean of its divisors is an integer number (859878852300).

Almost surely, 2^{21500235202645} is an apocalyptic number.

It is an amenable number.

21500235202645 is a deficient number, since it is larger than the sum of its proper divisors (6015888070955).

21500235202645 is a wasteful number, since it uses less digits than its factorization.

21500235202645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8596149.

The product of its (nonzero) digits is 144000, while the sum is 37.

The spelling of 21500235202645 in words is "twenty-one trillion, five hundred billion, two hundred thirty-five million, two hundred two thousand, six hundred forty-five".