1277781405120 has 672 divisors, whose sum is σ = 4837082365440. Its totient is φ = 307035463680.

The previous prime is 1277781405113. The next prime is 1277781405163. The reversal of 1277781405120 is 215041877721.

It is a happy number.

1277781405120 is a `hidden beast` number, since 1 + 27 + 7 + 78 + 1 + 40 + 512 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3218592762 + ... + 3218593158.

Almost surely, 2^{1277781405120} is an apocalyptic number.

1277781405120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1277781405120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2418541182720).

1277781405120 is an abundant number, since it is smaller than the sum of its proper divisors (3559300960320).

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

1277781405120 is a wasteful number, since it uses less digits than its factorization.

1277781405120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073 (or 1060 counting only the distinct ones).

The product of its (nonzero) digits is 219520, while the sum is 45.

The spelling of 1277781405120 in words is "one trillion, two hundred seventy-seven billion, seven hundred eighty-one million, four hundred five thousand, one hundred twenty".