1167778421 has 2 divisors, whose sum is σ = 1167778422. Its totient is φ = 1167778420.

The previous prime is 1167778369. The next prime is 1167778427. The reversal of 1167778421 is 1248777611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 800097796 + 367680625 = 28286^2 + 19175^2 .

It is a cyclic number.

It is not a de Polignac number, because 1167778421 - 2¹⁰ = 1167777397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1167778427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583889210 + 583889211.

It is an arithmetic number, because the mean of its divisors is an integer number (583889211).

Almost surely, 2^1167778421 is an apocalyptic number.

It is an amenable number.

1167778421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1167778421 is an equidigital number, since it uses as much as digits as its factorization.

1167778421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131712, while the sum is 44.

The square root of 1167778421 is about 34172.7730949655. The cubic root of 1167778421 is about 1053.0608858361.

The spelling of 1167778421 in words is "one billion, one hundred sixty-seven million, seven hundred seventy-eight thousand, four hundred twenty-one".