1611991245 has 32 divisors (see below), whose sum is σ = 2671056000. Its totient is φ = 829170944.

The previous prime is 1611991243. The next prime is 1611991279. The reversal of 1611991245 is 5421991161.

It is a cyclic number.

It is not a de Polignac number, because 1611991245 - 2¹ = 1611991243 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611991243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 595906 + ... + 598604.

It is an arithmetic number, because the mean of its divisors is an integer number (83470500).

Almost surely, 2^1611991245 is an apocalyptic number.

1611991245 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1611991245 is a deficient number, since it is larger than the sum of its proper divisors (1059064755).

1611991245 is a wasteful number, since it uses less digits than its factorization.

1611991245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4109.

The product of its digits is 19440, while the sum is 39.

The square root of 1611991245 is about 40149.6107702179. The cubic root of 1611991245 is about 1172.5217105680.

The spelling of 1611991245 in words is "one billion, six hundred eleven million, nine hundred ninety-one thousand, two hundred forty-five".