1491661545 has 32 divisors (see below), whose sum is σ = 2693416320. Its totient is φ = 698288640.

The previous prime is 1491661543. The next prime is 1491661579. The reversal of 1491661545 is 5451661941.

It is not a de Polignac number, because 1491661545 - 2¹ = 1491661543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1491661497 and 1491661506.

It is not an unprimeable number, because it can be changed into a prime (1491661543) 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 31 ways as a sum of consecutive naturals, for example, 151084 + ... + 160653.

It is an arithmetic number, because the mean of its divisors is an integer number (84169260).

Almost surely, 2^1491661545 is an apocalyptic number.

1491661545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1491661545 is a deficient number, since it is larger than the sum of its proper divisors (1201754775).

1491661545 is a wasteful number, since it uses less digits than its factorization.

1491661545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311785.

The product of its digits is 129600, while the sum is 42.

The square root of 1491661545 is about 38622.0344492623. The cubic root of 1491661545 is about 1142.5891558666.

The spelling of 1491661545 in words is "one billion, four hundred ninety-one million, six hundred sixty-one thousand, five hundred forty-five".