1531035661 has 4 divisors (see below), whose sum is σ = 1534892572. Its totient is φ = 1527178752.

The previous prime is 1531035619. The next prime is 1531035677. The reversal of 1531035661 is 1665301351.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 520113636 + 1010922025 = 22806^2 + 31795^2 .

It is a cyclic number.

It is not a de Polignac number, because 1531035661 - 2¹¹ = 1531033613 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 (1531035601) 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, 1927860 + ... + 1928653.

It is an arithmetic number, because the mean of its divisors is an integer number (383723143).

Almost surely, 2^1531035661 is an apocalyptic number.

It is an amenable number.

1531035661 is a deficient number, since it is larger than the sum of its proper divisors (3856911).

1531035661 is an equidigital number, since it uses as much as digits as its factorization.

1531035661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3856910.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 1531035661 is about 39128.4507871191. The cubic root of 1531035661 is about 1152.5552911144. Note that the first 3 decimals are identical.

The spelling of 1531035661 in words is "one billion, five hundred thirty-one million, thirty-five thousand, six hundred sixty-one".