1377628261 has 2 divisors, whose sum is σ = 1377628262. Its totient is φ = 1377628260.

The previous prime is 1377628247. The next prime is 1377628271. The reversal of 1377628261 is 1628267731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 997612225 + 380016036 = 31585^2 + 19494^2 .

It is an emirp because it is prime and its reverse (1628267731) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1377628261 - 2¹¹ = 1377626213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1377628211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 688814130 + 688814131.

It is an arithmetic number, because the mean of its divisors is an integer number (688814131).

Almost surely, 2^1377628261 is an apocalyptic number.

It is an amenable number.

1377628261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1377628261 is an equidigital number, since it uses as much as digits as its factorization.

1377628261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 43.

The square root of 1377628261 is about 37116.4149804369. The cubic root of 1377628261 is about 1112.6981034414.

The spelling of 1377628261 in words is "one billion, three hundred seventy-seven million, six hundred twenty-eight thousand, two hundred sixty-one".