1261115123877 has 80 divisors (see below), whose sum is σ = 2307130100352. Its totient is φ = 670074716160.

The previous prime is 1261115123833. The next prime is 1261115123893. The reversal of 1261115123877 is 7783215111621.

1261115123877 is a `hidden beast` number, since 1 + 2 + 61 + 1 + 1 + 512 + 3 + 8 + 77 = 666.

It is not a de Polignac number, because 1261115123877 - 2¹¹ = 1261115121829 is a prime.

It is a super-2 number, since 2×1261115123877² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261115123377) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 11877 + ... + 1588197.

Almost surely, 2^{1261115123877} is an apocalyptic number.

1261115123877 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1261115123877 is a deficient number, since it is larger than the sum of its proper divisors (1046014976475).

1261115123877 is a wasteful number, since it uses less digits than its factorization.

1261115123877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1576440 (or 1576431 counting only the distinct ones).

The product of its digits is 141120, while the sum is 45.

The spelling of 1261115123877 in words is "one trillion, two hundred sixty-one billion, one hundred fifteen million, one hundred twenty-three thousand, eight hundred seventy-seven".