21742015447 has 4 divisors (see below), whose sum is σ = 22443370816. Its totient is φ = 21040660080.

The previous prime is 21742015417. The next prime is 21742015543. The reversal of 21742015447 is 74451024712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21742015447 - 2¹⁹ = 21741491159 is a prime.

It is a super-3 number, since 3×21742015447³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21742015417) 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, 350677638 + ... + 350677699.

It is an arithmetic number, because the mean of its divisors is an integer number (5610842704).

Almost surely, 2^21742015447 is an apocalyptic number.

21742015447 is a deficient number, since it is larger than the sum of its proper divisors (701355369).

21742015447 is an equidigital number, since it uses as much as digits as its factorization.

21742015447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701355368.

The product of its (nonzero) digits is 62720, while the sum is 37.

The spelling of 21742015447 in words is "twenty-one billion, seven hundred forty-two million, fifteen thousand, four hundred forty-seven".