1272861820 has 12 divisors (see below), whose sum is σ = 2673009864. Its totient is φ = 509144720.

The previous prime is 1272861787. The next prime is 1272861841. The reversal of 1272861820 is 281682721.

It is a self number, because there is not a number n which added to its sum of digits gives 1272861820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31821526 + ... + 31821565.

It is an arithmetic number, because the mean of its divisors is an integer number (222750822).

Almost surely, 2^1272861820 is an apocalyptic number.

1272861820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1272861820 is an abundant number, since it is smaller than the sum of its proper divisors (1400148044).

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

1272861820 is a wasteful number, since it uses less digits than its factorization.

1272861820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63643100 (or 63643098 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 1272861820 is about 35677.1890708895. The cubic root of 1272861820 is about 1083.7449495944.

The spelling of 1272861820 in words is "one billion, two hundred seventy-two million, eight hundred sixty-one thousand, eight hundred twenty".