1211829887 has 12 divisors (see below), whose sum is σ = 1292140896. Its totient is φ = 1136263680.

The previous prime is 1211829841. The next prime is 1211829889. The reversal of 1211829887 is 7889281121.

It is not a de Polignac number, because 1211829887 - 2²⁰ = 1210781311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211829889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70583 + ... + 86055.

It is an arithmetic number, because the mean of its divisors is an integer number (107678408).

Almost surely, 2^1211829887 is an apocalyptic number.

1211829887 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1211829887 is a deficient number, since it is larger than the sum of its proper divisors (80311009).

1211829887 is a wasteful number, since it uses less digits than its factorization.

1211829887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15778 (or 15761 counting only the distinct ones).

The product of its digits is 129024, while the sum is 47.

The square root of 1211829887 is about 34811.3471011968. The cubic root of 1211829887 is about 1066.1391374670.

The spelling of 1211829887 in words is "one billion, two hundred eleven million, eight hundred twenty-nine thousand, eight hundred eighty-seven".