21506137735722 has 8 divisors (see below), whose sum is σ = 43012275471456. Its totient is φ = 7168712578572.

The previous prime is 21506137735721. The next prime is 21506137735769. The reversal of 21506137735722 is 22753773160512.

It is a sphenic number, since it is the product of 3 distinct primes.

21506137735722 is an admirable number.

It is a super-2 number, since 2×21506137735722² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21506137735721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1792178144638 + ... + 1792178144649.

It is an arithmetic number, because the mean of its divisors is an integer number (5376534433932).

Almost surely, 2^{21506137735722} is an apocalyptic number.

21506137735722 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21506137735722 is a wasteful number, since it uses less digits than its factorization.

21506137735722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3584356289292.

The product of its (nonzero) digits is 3704400, while the sum is 51.

The spelling of 21506137735722 in words is "twenty-one trillion, five hundred six billion, one hundred thirty-seven million, seven hundred thirty-five thousand, seven hundred twenty-two".