1261432723501 has 4 divisors (see below), whose sum is σ = 1265890083232. Its totient is φ = 1256975363772.

The previous prime is 1261432723489. The next prime is 1261432723531. The reversal of 1261432723501 is 1053272341621.

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 1261432723501 - 2⁵ = 1261432723469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261432723531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2228679441 + ... + 2228680006.

It is an arithmetic number, because the mean of its divisors is an integer number (316472520808).

Almost surely, 2^{1261432723501} is an apocalyptic number.

It is an amenable number.

1261432723501 is a deficient number, since it is larger than the sum of its proper divisors (4457359731).

1261432723501 is an equidigital number, since it uses as much as digits as its factorization.

1261432723501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4457359730.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 1261432723501 in words is "one trillion, two hundred sixty-one billion, four hundred thirty-two million, seven hundred twenty-three thousand, five hundred one".