21621351111442 has 16 divisors (see below), whose sum is σ = 34339899017952. Its totient is φ = 10174722034240.

The previous prime is 21621351111389. The next prime is 21621351111467. The reversal of 21621351111442 is 24411115312612.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 21621351111398 and 21621351111407.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13121517 + ... + 14677087.

It is an arithmetic number, because the mean of its divisors is an integer number (2146243688622).

Almost surely, 2^{21621351111442} is an apocalyptic number.

21621351111442 is a deficient number, since it is larger than the sum of its proper divisors (12718547906510).

21621351111442 is a wasteful number, since it uses less digits than its factorization.

21621351111442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964393.

The product of its digits is 11520, while the sum is 34.

The spelling of 21621351111442 in words is "twenty-one trillion, six hundred twenty-one billion, three hundred fifty-one million, one hundred eleven thousand, four hundred forty-two".