1019881649 has 4 divisors (see below), whose sum is σ = 1021926000. Its totient is φ = 1017837300.

The previous prime is 1019881619. The next prime is 1019881691. The reversal of 1019881649 is 9461889101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1019881649 - 2²⁴ = 1003104433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1019881609) 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, 1021427 + ... + 1022424.

It is an arithmetic number, because the mean of its divisors is an integer number (255481500).

Almost surely, 2^1019881649 is an apocalyptic number.

It is an amenable number.

1019881649 is a deficient number, since it is larger than the sum of its proper divisors (2044351).

1019881649 is an equidigital number, since it uses as much as digits as its factorization.

1019881649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2044350.

The product of its (nonzero) digits is 124416, while the sum is 47.

The square root of 1019881649 is about 31935.5859348157. The cubic root of 1019881649 is about 1006.5837751116.

The spelling of 1019881649 in words is "one billion, nineteen million, eight hundred eighty-one thousand, six hundred forty-nine".