1611490781 has 2 divisors, whose sum is σ = 1611490782. Its totient is φ = 1611490780.

The previous prime is 1611490759. The next prime is 1611490789. The reversal of 1611490781 is 1870941161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1607288281 + 4202500 = 40091^2 + 2050^2 .

It is an emirp because it is prime and its reverse (1870941161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1611490781 - 2⁶ = 1611490717 is a prime.

It is a super-2 number, since 2×1611490781² = 5193805074495979922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1611490789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 805745390 + 805745391.

It is an arithmetic number, because the mean of its divisors is an integer number (805745391).

Almost surely, 2^1611490781 is an apocalyptic number.

It is an amenable number.

1611490781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1611490781 is an equidigital number, since it uses as much as digits as its factorization.

1611490781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 38.

The square root of 1611490781 is about 40143.3777975895. The cubic root of 1611490781 is about 1172.4003563847.

The spelling of 1611490781 in words is "one billion, six hundred eleven million, four hundred ninety thousand, seven hundred eighty-one".