1213211987 has 32 divisors (see below), whose sum is σ = 1421328384. Its totient is φ = 1025395200.

The previous prime is 1213211977. The next prime is 1213211999. The reversal of 1213211987 is 7891123121.

It is a cyclic number.

It is not a de Polignac number, because 1213211987 - 2¹⁴ = 1213195603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1213211917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2814662 + ... + 2815092.

It is an arithmetic number, because the mean of its divisors is an integer number (44416512).

Almost surely, 2^1213211987 is an apocalyptic number.

1213211987 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1213211987 is a deficient number, since it is larger than the sum of its proper divisors (208116397).

1213211987 is a wasteful number, since it uses less digits than its factorization.

1213211987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779.

The product of its digits is 6048, while the sum is 35.

The square root of 1213211987 is about 34831.1927300803. The cubic root of 1213211987 is about 1066.5442963895.

The spelling of 1213211987 in words is "one billion, two hundred thirteen million, two hundred eleven thousand, nine hundred eighty-seven".