1221513899 has 2 divisors, whose sum is σ = 1221513900. Its totient is φ = 1221513898.

The previous prime is 1221513859. The next prime is 1221513941. The reversal of 1221513899 is 9983151221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221513899 - 2¹⁶ = 1221448363 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221513859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610756949 + 610756950.

It is an arithmetic number, because the mean of its divisors is an integer number (610756950).

Almost surely, 2^1221513899 is an apocalyptic number.

1221513899 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221513899 is an equidigital number, since it uses as much as digits as its factorization.

1221513899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 41.

The square root of 1221513899 is about 34950.1630754422. The cubic root of 1221513899 is about 1068.9715272631.

The spelling of 1221513899 in words is "one billion, two hundred twenty-one million, five hundred thirteen thousand, eight hundred ninety-nine".