21345337421 has 16 divisors (see below), whose sum is σ = 21696030720. Its totient is φ = 20998232640.

The previous prime is 21345337397. The next prime is 21345337441. The reversal of 21345337421 is 12473354312.

It is a cyclic number.

It is not a de Polignac number, because 21345337421 - 2⁶ = 21345337357 is a prime.

It is a super-3 number, since 3×21345337421³ (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 (21345337441) 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, 9124670 + ... + 9127008.

It is an arithmetic number, because the mean of its divisors is an integer number (1356001920).

Almost surely, 2^21345337421 is an apocalyptic number.

It is an amenable number.

21345337421 is a deficient number, since it is larger than the sum of its proper divisors (350693299).

21345337421 is a wasteful number, since it uses less digits than its factorization.

21345337421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3044.

The product of its digits is 60480, while the sum is 35.

The spelling of 21345337421 in words is "twenty-one billion, three hundred forty-five million, three hundred thirty-seven thousand, four hundred twenty-one".