8378121511 has 2 divisors, whose sum is σ = 8378121512. Its totient is φ = 8378121510.

The previous prime is 8378121503. The next prime is 8378121517. The reversal of 8378121511 is 1151218738.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8378121511 - 2³ = 8378121503 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8378121517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4189060755 + 4189060756.

It is an arithmetic number, because the mean of its divisors is an integer number (4189060756).

Almost surely, 2^8378121511 is an apocalyptic number.

8378121511 is a deficient number, since it is larger than the sum of its proper divisors (1).

8378121511 is an equidigital number, since it uses as much as digits as its factorization.

8378121511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 37.

The square root of 8378121511 is about 91532.0791362241. The cubic root of 8378121511 is about 2031.0263207158.

The spelling of 8378121511 in words is "eight billion, three hundred seventy-eight million, one hundred twenty-one thousand, five hundred eleven".