1278215620 has 24 divisors (see below), whose sum is σ = 2928276288. Its totient is φ = 464805600.

The previous prime is 1278215573. The next prime is 1278215663. The reversal of 1278215620 is 265128721.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2904816 + ... + 2905255.

It is an arithmetic number, because the mean of its divisors is an integer number (122011512).

Almost surely, 2^1278215620 is an apocalyptic number.

1278215620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1278215620 is an abundant number, since it is smaller than the sum of its proper divisors (1650060668).

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

1278215620 is a wasteful number, since it uses less digits than its factorization.

1278215620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5810091 (or 5810089 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 1278215620 is about 35752.1414743229. The cubic root of 1278215620 is about 1085.2622752875.

The spelling of 1278215620 in words is "one billion, two hundred seventy-eight million, two hundred fifteen thousand, six hundred twenty".