8420815403491 has 2 divisors, whose sum is σ = 8420815403492. Its totient is φ = 8420815403490.

The previous prime is 8420815403419. The next prime is 8420815403519. The reversal of 8420815403491 is 1943045180248.

Together with previous prime (8420815403419) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8420815403491 - 2¹³ = 8420815395299 is a prime.

It is not a weakly prime, because it can be changed into another prime (8420815403291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4210407701745 + 4210407701746.

It is an arithmetic number, because the mean of its divisors is an integer number (4210407701746).

Almost surely, 2^{8420815403491} is an apocalyptic number.

8420815403491 is a deficient number, since it is larger than the sum of its proper divisors (1).

8420815403491 is an equidigital number, since it uses as much as digits as its factorization.

8420815403491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1105920, while the sum is 49.

The spelling of 8420815403491 in words is "eight trillion, four hundred twenty billion, eight hundred fifteen million, four hundred three thousand, four hundred ninety-one".