1531757661 has 16 divisors (see below), whose sum is σ = 2335029888. Its totient is φ = 874944000.

The previous prime is 1531757659. The next prime is 1531757687. The reversal of 1531757661 is 1667571351.

It is not a de Polignac number, because 1531757661 - 2¹ = 1531757659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531757651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45801 + ... + 71841.

It is an arithmetic number, because the mean of its divisors is an integer number (145939368).

Almost surely, 2^1531757661 is an apocalyptic number.

It is an amenable number.

1531757661 is a deficient number, since it is larger than the sum of its proper divisors (803272227).

1531757661 is a wasteful number, since it uses less digits than its factorization.

1531757661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28852.

The product of its digits is 132300, while the sum is 42.

The square root of 1531757661 is about 39137.6757230166. The cubic root of 1531757661 is about 1152.7364351964.

The spelling of 1531757661 in words is "one billion, five hundred thirty-one million, seven hundred fifty-seven thousand, six hundred sixty-one".