127780381 has 4 divisors (see below), whose sum is σ = 135296892. Its totient is φ = 120263872.

The previous prime is 127780327. The next prime is 127780423. The reversal of 127780381 is 183087721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 83557881 + 44222500 = 9141^2 + 6650^2 .

It is a cyclic number.

It is not a de Polignac number, because 127780381 - 2¹¹ = 127778333 is a prime.

It is a super-2 number, since 2×127780381² = 32655651537010322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 127780381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (127780181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3758230 + ... + 3758263.

It is an arithmetic number, because the mean of its divisors is an integer number (33824223).

Almost surely, 2^127780381 is an apocalyptic number.

It is an amenable number.

127780381 is a deficient number, since it is larger than the sum of its proper divisors (7516511).

127780381 is an equidigital number, since it uses as much as digits as its factorization.

127780381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7516510.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 127780381 is about 11303.9984518753. The cubic root of 127780381 is about 503.6800230777.

The spelling of 127780381 in words is "one hundred twenty-seven million, seven hundred eighty thousand, three hundred eighty-one".