1231601553 has 24 divisors (see below), whose sum is σ = 2189515328. Its totient is φ = 649635552.

The previous prime is 1231601549. The next prime is 1231601561. The reversal of 1231601553 is 3551061321.

1231601553 is a `hidden beast` number, since 1 + 2 + 3 + 1 + 601 + 5 + 53 = 666.

It is not a de Polignac number, because 1231601553 - 2² = 1231601549 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231601513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 751075 + ... + 752712.

Almost surely, 2^1231601553 is an apocalyptic number.

1231601553 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1231601553 is a deficient number, since it is larger than the sum of its proper divisors (957913775).

1231601553 is a wasteful number, since it uses less digits than its factorization.

1231601553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1503813 (or 1503810 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 1231601553 is about 35094.1811843502. The cubic root of 1231601553 is about 1071.9061005157.

Adding to 1231601553 its reverse (3551061321), we get a palindrome (4782662874).

The spelling of 1231601553 in words is "one billion, two hundred thirty-one million, six hundred one thousand, five hundred fifty-three".