1261782885 has 32 divisors (see below), whose sum is σ = 2207761920. Its totient is φ = 610280000.

The previous prime is 1261782883. The next prime is 1261782911. The reversal of 1261782885 is 5882871621.

It is not a de Polignac number, because 1261782885 - 2¹ = 1261782883 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261782883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60010 + ... + 78260.

It is an arithmetic number, because the mean of its divisors is an integer number (68992560).

Almost surely, 2^1261782885 is an apocalyptic number.

1261782885 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261782885 is a deficient number, since it is larger than the sum of its proper divisors (945979035).

1261782885 is a wasteful number, since it uses less digits than its factorization.

1261782885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18689.

The product of its digits is 430080, while the sum is 48.

The square root of 1261782885 is about 35521.5833684255. The cubic root of 1261782885 is about 1080.5914926940.

The spelling of 1261782885 in words is "one billion, two hundred sixty-one million, seven hundred eighty-two thousand, eight hundred eighty-five".