1219531381 has 2 divisors, whose sum is σ = 1219531382. Its totient is φ = 1219531380.

The previous prime is 1219531319. The next prime is 1219531399. The reversal of 1219531381 is 1831359121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1112222500 + 107308881 = 33350^2 + 10359^2 .

It is a cyclic number.

It is not a de Polignac number, because 1219531381 - 2²⁵ = 1185976949 is a prime.

It is a super-2 number, since 2×1219531381² = 2974513578487534322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1219531081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609765690 + 609765691.

It is an arithmetic number, because the mean of its divisors is an integer number (609765691).

Almost surely, 2^1219531381 is an apocalyptic number.

It is an amenable number.

1219531381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1219531381 is an equidigital number, since it uses as much as digits as its factorization.

1219531381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 34.

The square root of 1219531381 is about 34921.7894873673. The cubic root of 1219531381 is about 1068.3929002417.

The spelling of 1219531381 in words is "one billion, two hundred nineteen million, five hundred thirty-one thousand, three hundred eighty-one".