21506075433764 has 6 divisors (see below), whose sum is σ = 37635632009094. Its totient is φ = 10753037716880.

The previous prime is 21506075433763. The next prime is 21506075433797. The reversal of 21506075433764 is 46733457060512.

It can be written as a sum of positive squares in only one way, i.e., 21374052211264 + 132023222500 = 4623208^2 + 363350^2 .

It is a super-2 number, since 2×21506075433764² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21506075433763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2688259429217 + ... + 2688259429224.

It is an arithmetic number, because the mean of its divisors is an integer number (6272605334849).

Almost surely, 2^{21506075433764} is an apocalyptic number.

It is an amenable number.

21506075433764 is a deficient number, since it is larger than the sum of its proper divisors (16129556575330).

21506075433764 is a wasteful number, since it uses less digits than its factorization.

21506075433764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5376518858445 (or 5376518858443 counting only the distinct ones).

The product of its (nonzero) digits is 12700800, while the sum is 53.

The spelling of 21506075433764 in words is "twenty-one trillion, five hundred six billion, seventy-five million, four hundred thirty-three thousand, seven hundred sixty-four".