21506071547365 has 8 divisors (see below), whose sum is σ = 25817780904480. Its totient is φ = 17197860539472.

The previous prime is 21506071547357. The next prime is 21506071547399. The reversal of 21506071547365 is 56374517060512.

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

It is a cyclic number.

It is not a de Polignac number, because 21506071547365 - 2³ = 21506071547357 is a prime.

It is a super-2 number, since 2×21506071547365² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 874573779 + ... + 874598368.

It is an arithmetic number, because the mean of its divisors is an integer number (3227222613060).

Almost surely, 2^{21506071547365} is an apocalyptic number.

It is an amenable number.

21506071547365 is a deficient number, since it is larger than the sum of its proper divisors (4311709357115).

21506071547365 is a wasteful number, since it uses less digits than its factorization.

21506071547365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749174611.

The product of its (nonzero) digits is 5292000, while the sum is 52.

The spelling of 21506071547365 in words is "twenty-one trillion, five hundred six billion, seventy-one million, five hundred forty-seven thousand, three hundred sixty-five".