3661249491 has 20 divisors (see below), whose sum is σ = 5596471672. Its totient is φ = 2384067168.

The previous prime is 3661249483. The next prime is 3661249583. The reversal of 3661249491 is 1949421663.

3661249491 is a `hidden beast` number, since 3 + 66 + 12 + 494 + 91 = 666.

It is not a de Polignac number, because 3661249491 - 2³ = 3661249483 is a prime.

It is a super-3 number, since 3×3661249491³ (a number of 30 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (3661245491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 522106 + ... + 529071.

Almost surely, 2^3661249491 is an apocalyptic number.

3661249491 is a deficient number, since it is larger than the sum of its proper divisors (1935222181).

3661249491 is a wasteful number, since it uses less digits than its factorization.

3661249491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051232 (or 1051223 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 3661249491 is about 60508.2596923759. The cubic root of 3661249491 is about 1541.2618952320.

The spelling of 3661249491 in words is "three billion, six hundred sixty-one million, two hundred forty-nine thousand, four hundred ninety-one".