1377673561 has 4 divisors (see below), whose sum is σ = 1502916624. Its totient is φ = 1252430500.

The previous prime is 1377673537. The next prime is 1377673567. The reversal of 1377673561 is 1653767731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1377673561 - 2⁵ = 1377673529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1377673567) 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, 62621515 + ... + 62621536.

It is an arithmetic number, because the mean of its divisors is an integer number (375729156).

Almost surely, 2^1377673561 is an apocalyptic number.

1377673561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1377673561 is a deficient number, since it is larger than the sum of its proper divisors (125243063).

1377673561 is a wasteful number, since it uses less digits than its factorization.

1377673561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125243062.

The product of its digits is 555660, while the sum is 46.

The square root of 1377673561 is about 37117.0252175467. The cubic root of 1377673561 is about 1112.7102994435.

The spelling of 1377673561 in words is "one billion, three hundred seventy-seven million, six hundred seventy-three thousand, five hundred sixty-one".