1231556160025 has 9 divisors (see below), whose sum is σ = 1527136518943. Its totient is φ = 985240489000.

The previous prime is 1231556160019. The next prime is 1231556160031. The reversal of 1231556160025 is 5200616551321.

It is a happy number.

The square root of 1231556160025 is 1109755.

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 (1231556160019) and next prime (1231556160031).

It can be written as a sum of positive squares in only one way, i.e., 443360217609 + 788195942416 = 665853^2 + 887804^2 .

It is not a de Polignac number, because 1231556160025 - 2⁵ = 1231556159993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5437800 + ... + 5659750.

Almost surely, 2^{1231556160025} is an apocalyptic number.

1231556160025 is the 1109755-th square number.

1231556160025 is the 554878-th centered octagonal number.

It is an amenable number.

1231556160025 is a deficient number, since it is larger than the sum of its proper divisors (295580358918).

1231556160025 is an frugal number, since it uses more digits than its factorization.

1231556160025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443912 (or 221956 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 1231556160025 in words is "one trillion, two hundred thirty-one billion, five hundred fifty-six million, one hundred sixty thousand, twenty-five".