21408733333421 has 16 divisors (see below), whose sum is σ = 24572475592704. Its totient is φ = 18271498767984.

The previous prime is 21408733333369. The next prime is 21408733333423. The reversal of 21408733333421 is 12433333780412.

It is not a de Polignac number, because 21408733333421 - 2³⁰ = 21407659591597 is a prime.

It is a super-5 number, since 5×21408733333421⁵ (a number of 68 digits) contains 55555 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 (21408733333423) 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, 5558825 + ... + 8585918.

It is an arithmetic number, because the mean of its divisors is an integer number (1535779724544).

Almost surely, 2^{21408733333421} is an apocalyptic number.

It is an amenable number.

21408733333421 is a deficient number, since it is larger than the sum of its proper divisors (3163742259283).

21408733333421 is a wasteful number, since it uses less digits than its factorization.

21408733333421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14145680.

The product of its (nonzero) digits is 870912, while the sum is 44.

The spelling of 21408733333421 in words is "twenty-one trillion, four hundred eight billion, seven hundred thirty-three million, three hundred thirty-three thousand, four hundred twenty-one".