1213565501 has 2 divisors, whose sum is σ = 1213565502. Its totient is φ = 1213565500.

The previous prime is 1213565497. The next prime is 1213565503. The reversal of 1213565501 is 1055653121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1028741476 + 184824025 = 32074^2 + 13595^2 .

It is an emirp because it is prime and its reverse (1055653121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1213565501 - 2² = 1213565497 is a prime.

Together with 1213565503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213565503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606782750 + 606782751.

It is an arithmetic number, because the mean of its divisors is an integer number (606782751).

Almost surely, 2^1213565501 is an apocalyptic number.

It is an amenable number.

1213565501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213565501 is an equidigital number, since it uses as much as digits as its factorization.

1213565501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 1213565501 is about 34836.2670359498. The cubic root of 1213565501 is about 1066.6478786513.

The spelling of 1213565501 in words is "one billion, two hundred thirteen million, five hundred sixty-five thousand, five hundred one".