1261077342529 has 9 divisors (see below), whose sum is σ = 1264840380993. Its totient is φ = 1257325476372.

The previous prime is 1261077342517. The next prime is 1261077342541. The reversal of 1261077342529 is 9252437701621.

The square root of 1261077342529 is 1122977.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (1261077342517) and next prime (1261077342541).

It is not a de Polignac number, because 1261077342529 - 2⁹ = 1261077342017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261077342589) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 425606802 + ... + 425609764.

Almost surely, 2^{1261077342529} is an apocalyptic number.

1261077342529 is the 1122977-th square number.

1261077342529 is the 561489-th centered octagonal number.

It is an amenable number.

1261077342529 is a deficient number, since it is larger than the sum of its proper divisors (3763038464).

1261077342529 is an frugal number, since it uses more digits than its factorization.

1261077342529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6684 (or 3342 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 49.

Multiplying 1261077342529 by its sum of digits (49), we get a square (61792789783921 = 7860839²).

The spelling of 1261077342529 in words is "one trillion, two hundred sixty-one billion, seventy-seven million, three hundred forty-two thousand, five hundred twenty-nine".