1201731557 has 4 divisors (see below), whose sum is σ = 1294172460. Its totient is φ = 1109290656.

The previous prime is 1201731541. The next prime is 1201731563. The reversal of 1201731557 is 7551371021.

It is a Cunningham number, because it is equal to 34666²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7551371021 = 41 ⋅184179781.

It can be written as a sum of positive squares in 2 ways, for example, as 177795556 + 1023936001 = 13334^2 + 31999^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201731557 - 2⁴ = 1201731541 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 (1201731527) 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, 46220432 + ... + 46220457.

It is an arithmetic number, because the mean of its divisors is an integer number (323543115).

Almost surely, 2^1201731557 is an apocalyptic number.

It is an amenable number.

1201731557 is a deficient number, since it is larger than the sum of its proper divisors (92440903).

1201731557 is an equidigital number, since it uses as much as digits as its factorization.

1201731557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92440902.

The product of its (nonzero) digits is 7350, while the sum is 32.

The square root of 1201731557 is about 34666.0000144234. Note that the first 4 decimals coincide. The cubic root of 1201731557 is about 1063.1694496129.

The spelling of 1201731557 in words is "one billion, two hundred one million, seven hundred thirty-one thousand, five hundred fifty-seven".