781272120 has 64 divisors (see below), whose sum is σ = 2345656320. Its totient is φ = 208175744.

The previous prime is 781272091. The next prime is 781272127. The reversal of 781272120 is 21272187.

It is a happy number.

It is a super-2 number, since 2×781272120² = 1220772250978588800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781272127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289417 + ... + 292103.

It is an arithmetic number, because the mean of its divisors is an integer number (36650880).

Almost surely, 2^781272120 is an apocalyptic number.

It is an amenable number.

781272120 is an abundant number, since it is smaller than the sum of its proper divisors (1564384200).

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

781272120 is a wasteful number, since it uses less digits than its factorization.

781272120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5124 (or 5120 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 781272120 is about 27951.2454105358. The cubic root of 781272120 is about 921.0165669276.

The spelling of 781272120 in words is "seven hundred eighty-one million, two hundred seventy-two thousand, one hundred twenty".