21661030401443 has 2 divisors, whose sum is σ = 21661030401444. Its totient is φ = 21661030401442.

The previous prime is 21661030401433. The next prime is 21661030401463. The reversal of 21661030401443 is 34410403016612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21661030401443 - 2¹⁸ = 21661030139299 is a prime.

It is a super-3 number, since 3×21661030401443³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21661030401433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830515200721 + 10830515200722.

It is an arithmetic number, because the mean of its divisors is an integer number (10830515200722).

Almost surely, 2^{21661030401443} is an apocalyptic number.

21661030401443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21661030401443 is an equidigital number, since it uses as much as digits as its factorization.

21661030401443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 35.

The spelling of 21661030401443 in words is "twenty-one trillion, six hundred sixty-one billion, thirty million, four hundred one thousand, four hundred forty-three".