21621211401343 has 16 divisors (see below), whose sum is σ = 22267531139040. Its totient is φ = 20984355310464.

The previous prime is 21621211401301. The next prime is 21621211401403. The reversal of 21621211401343 is 34310411212612.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21621211401343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621211441343) 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, 488580 + ... + 6594022.

It is an arithmetic number, because the mean of its divisors is an integer number (1391720696190).

Almost surely, 2^{21621211401343} is an apocalyptic number.

21621211401343 is a deficient number, since it is larger than the sum of its proper divisors (646319737697).

21621211401343 is a wasteful number, since it uses less digits than its factorization.

21621211401343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6106218.

The product of its (nonzero) digits is 6912, while the sum is 31.

Adding to 21621211401343 its reverse (34310411212612), we get a palindrome (55931622613955).

The spelling of 21621211401343 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred eleven million, four hundred one thousand, three hundred forty-three".