1271787642 has 48 divisors (see below), whose sum is σ = 2897923392. Its totient is φ = 417947040.

The previous prime is 1271787637. The next prime is 1271787701. The reversal of 1271787642 is 2467871721.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16078 + ... + 52934.

It is an arithmetic number, because the mean of its divisors is an integer number (60373404).

Almost surely, 2^1271787642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1271787642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1448961696).

1271787642 is an abundant number, since it is smaller than the sum of its proper divisors (1626135750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1271787642 is an equidigital number, since it uses as much as digits as its factorization.

1271787642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36945 (or 36933 counting only the distinct ones).

The product of its digits is 263424, while the sum is 45.

The square root of 1271787642 is about 35662.1317646604. The cubic root of 1271787642 is about 1083.4400035293.

The spelling of 1271787642 in words is "one billion, two hundred seventy-one million, seven hundred eighty-seven thousand, six hundred forty-two".