1209613881 has 16 divisors (see below), whose sum is σ = 1845341568. Its totient is φ = 690412800.

The previous prime is 1209613871. The next prime is 1209613919. The reversal of 1209613881 is 1883169021.

It is not a de Polignac number, because 1209613881 - 2⁹ = 1209613369 is a prime.

It is a super-2 number, since 2×1209613881² = 2926331482215764322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1209613841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14190 + ... + 51191.

It is an arithmetic number, because the mean of its divisors is an integer number (115333848).

Almost surely, 2^1209613881 is an apocalyptic number.

It is an amenable number.

1209613881 is a deficient number, since it is larger than the sum of its proper divisors (635727687).

1209613881 is an equidigital number, since it uses as much as digits as its factorization.

1209613881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66272.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 1209613881 is about 34779.5037486161. The cubic root of 1209613881 is about 1065.4888778015.

The spelling of 1209613881 in words is "one billion, two hundred nine million, six hundred thirteen thousand, eight hundred eighty-one".