1278542840 has 32 divisors (see below), whose sum is σ = 2905212960. Its totient is φ = 506352000.

The previous prime is 1278542831. The next prime is 1278542849. The reversal of 1278542840 is 482458721.

It is an interprime number because it is at equal distance from previous prime (1278542831) and next prime (1278542849).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278542849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154196 + ... + 162275.

It is an arithmetic number, because the mean of its divisors is an integer number (90787905).

Almost surely, 2^1278542840 is an apocalyptic number.

1278542840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1278542840 is an abundant number, since it is smaller than the sum of its proper divisors (1626670120).

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

1278542840 is a wasteful number, since it uses less digits than its factorization.

1278542840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316583 (or 316579 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 41.

The square root of 1278542840 is about 35756.7174108586. The cubic root of 1278542840 is about 1085.3548755283.

The spelling of 1278542840 in words is "one billion, two hundred seventy-eight million, five hundred forty-two thousand, eight hundred forty".