21421378403611 has 2 divisors, whose sum is σ = 21421378403612. Its totient is φ = 21421378403610.

The previous prime is 21421378403597. The next prime is 21421378403653. The reversal of 21421378403611 is 11630487312412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21421378403611 - 2¹³ = 21421378395419 is a prime.

It is not a weakly prime, because it can be changed into another prime (21421378403681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710689201805 + 10710689201806.

It is an arithmetic number, because the mean of its divisors is an integer number (10710689201806).

Almost surely, 2^{21421378403611} is an apocalyptic number.

21421378403611 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421378403611 is an equidigital number, since it uses as much as digits as its factorization.

21421378403611 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 43.

The spelling of 21421378403611 in words is "twenty-one trillion, four hundred twenty-one billion, three hundred seventy-eight million, four hundred three thousand, six hundred eleven".