1531621161 has 24 divisors (see below), whose sum is σ = 2558861760. Its totient is φ = 864664416.

The previous prime is 1531621127. The next prime is 1531621163. The reversal of 1531621161 is 1611261351.

1531621161 is a `hidden beast` number, since 1 + 5 + 31 + 621 + 1 + 6 + 1 = 666.

It is not a de Polignac number, because 1531621161 - 2⁷ = 1531621033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1531621163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 141226 + ... + 151683.

It is an arithmetic number, because the mean of its divisors is an integer number (106619240).

Almost surely, 2^1531621161 is an apocalyptic number.

It is an amenable number.

1531621161 is a deficient number, since it is larger than the sum of its proper divisors (1027240599).

1531621161 is a wasteful number, since it uses less digits than its factorization.

1531621161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293005 (or 293002 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 1531621161 is about 39135.9318401900. The cubic root of 1531621161 is about 1152.7021927916.

The spelling of 1531621161 in words is "one billion, five hundred thirty-one million, six hundred twenty-one thousand, one hundred sixty-one".