1201559881 has 4 divisors (see below), whose sum is σ = 1272239892. Its totient is φ = 1130879872.

The previous prime is 1201559869. The next prime is 1201559911. The reversal of 1201559881 is 1889551021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1889551021 = 43 ⋅43943047.

It can be written as a sum of positive squares in 2 ways, for example, as 951414025 + 250145856 = 30845^2 + 15816^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201559881 - 2⁹ = 1201559369 is a prime.

It is a super-2 number, since 2×1201559881² = 2887492295257468322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1201559831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35339980 + ... + 35340013.

It is an arithmetic number, because the mean of its divisors is an integer number (318059973).

Almost surely, 2^1201559881 is an apocalyptic number.

It is an amenable number.

1201559881 is a deficient number, since it is larger than the sum of its proper divisors (70680011).

1201559881 is an equidigital number, since it uses as much as digits as its factorization.

1201559881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70680010.

The product of its (nonzero) digits is 28800, while the sum is 40.

The square root of 1201559881 is about 34663.5237822123. The cubic root of 1201559881 is about 1063.1188200666.

It can be divided in two parts, 120 and 1559881, that added together give a square (1560001 = 1249²).

The spelling of 1201559881 in words is "one billion, two hundred one million, five hundred fifty-nine thousand, eight hundred eighty-one".