21621404031342 has 16 divisors (see below), whose sum is σ = 43492766492880. Its totient is φ = 7165474938752.

The previous prime is 21621404031323. The next prime is 21621404031347. The reversal of 21621404031342 is 24313040412612.

It is a super-2 number, since 2×21621404031342² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621404031347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10414933467 + ... + 10414935542.

It is an arithmetic number, because the mean of its divisors is an integer number (2718297905805).

Almost surely, 2^{21621404031342} is an apocalyptic number.

21621404031342 is an abundant number, since it is smaller than the sum of its proper divisors (21871362461538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21621404031342 is a wasteful number, since it uses less digits than its factorization.

21621404031342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20829869187.

The product of its (nonzero) digits is 27648, while the sum is 33.

Adding to 21621404031342 its reverse (24313040412612), we get a palindrome (45934444443954).

The spelling of 21621404031342 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred four million, thirty-one thousand, three hundred forty-two".