1212178157 has 2 divisors, whose sum is σ = 1212178158. Its totient is φ = 1212178156.

The previous prime is 1212178139. The next prime is 1212178171. The reversal of 1212178157 is 7518712121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1111155556 + 101022601 = 33334^2 + 10051^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212178157 - 2¹⁶ = 1212112621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212178657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606089078 + 606089079.

It is an arithmetic number, because the mean of its divisors is an integer number (606089079).

Almost surely, 2^1212178157 is an apocalyptic number.

It is an amenable number.

1212178157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212178157 is an equidigital number, since it uses as much as digits as its factorization.

1212178157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7840, while the sum is 35.

The square root of 1212178157 is about 34816.3489900937. The cubic root of 1212178157 is about 1066.2412609078.

The spelling of 1212178157 in words is "one billion, two hundred twelve million, one hundred seventy-eight thousand, one hundred fifty-seven".