1619964491 has 4 divisors (see below), whose sum is σ = 1705225800. Its totient is φ = 1534703184.

The previous prime is 1619964469. The next prime is 1619964517. The reversal of 1619964491 is 1944699161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1619964491 - 2²² = 1615770187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1619964191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42630626 + ... + 42630663.

It is an arithmetic number, because the mean of its divisors is an integer number (426306450).

Almost surely, 2^1619964491 is an apocalyptic number.

1619964491 is a deficient number, since it is larger than the sum of its proper divisors (85261309).

1619964491 is an equidigital number, since it uses as much as digits as its factorization.

1619964491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85261308.

The product of its digits is 419904, while the sum is 50.

The square root of 1619964491 is about 40248.7824784800. The cubic root of 1619964491 is about 1174.4517112364.

The spelling of 1619964491 in words is "one billion, six hundred nineteen million, nine hundred sixty-four thousand, four hundred ninety-one".