1491640819 has 2 divisors, whose sum is σ = 1491640820. Its totient is φ = 1491640818.

The previous prime is 1491640811. The next prime is 1491640823. The reversal of 1491640819 is 9180461941.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1491640819 - 2³ = 1491640811 is a prime.

It is a super-2 number, since 2×1491640819² = 4449984665813981522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1491640811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745820409 + 745820410.

It is an arithmetic number, because the mean of its divisors is an integer number (745820410).

Almost surely, 2^1491640819 is an apocalyptic number.

1491640819 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491640819 is an equidigital number, since it uses as much as digits as its factorization.

1491640819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 1491640819 is about 38621.7661299946. The cubic root of 1491640819 is about 1142.5838639127.

The spelling of 1491640819 in words is "one billion, four hundred ninety-one million, six hundred forty thousand, eight hundred nineteen".