21621411347523 has 16 divisors (see below), whose sum is σ = 31046613255840. Its totient is φ = 13305276417024.

The previous prime is 21621411347489. The next prime is 21621411347539. The reversal of 21621411347523 is 32574311412612.

It is a happy number.

It is not a de Polignac number, because 21621411347523 - 2³² = 21617116380227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21621411347623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1770636 + ... + 6810137.

It is an arithmetic number, because the mean of its divisors is an integer number (1940413328490).

Almost surely, 2^{21621411347523} is an apocalyptic number.

21621411347523 is a deficient number, since it is larger than the sum of its proper divisors (9425201908317).

21621411347523 is a wasteful number, since it uses less digits than its factorization.

21621411347523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8645398.

The product of its digits is 241920, while the sum is 42.

The spelling of 21621411347523 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred eleven million, three hundred forty-seven thousand, five hundred twenty-three".