1612187491 has 4 divisors (see below), whose sum is σ = 1613427984. Its totient is φ = 1610947000.

The previous prime is 1612187477. The next prime is 1612187497. The reversal of 1612187491 is 1947812161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1947812161 = 2741 ⋅710621.

It is a cyclic number.

It is not a de Polignac number, because 1612187491 - 2¹⁷ = 1612056419 is a prime.

It is a super-2 number, since 2×1612187491² = 5198297012273750162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1612187497) 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 3 ways as a sum of consecutive naturals, for example, 618295 + ... + 620896.

It is an arithmetic number, because the mean of its divisors is an integer number (403356996).

Almost surely, 2^1612187491 is an apocalyptic number.

1612187491 is a deficient number, since it is larger than the sum of its proper divisors (1240493).

1612187491 is a wasteful number, since it uses less digits than its factorization.

1612187491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1240492.

The product of its digits is 24192, while the sum is 40.

The square root of 1612187491 is about 40152.0546298692. The cubic root of 1612187491 is about 1172.5692900982.

The spelling of 1612187491 in words is "one billion, six hundred twelve million, one hundred eighty-seven thousand, four hundred ninety-one".