1649940863 has 4 divisors (see below), whose sum is σ = 1650553080. Its totient is φ = 1649328648.

The previous prime is 1649940823. The next prime is 1649940881. The reversal of 1649940863 is 3680499461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1649940863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1649940823) 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, 302048 + ... + 307461.

It is an arithmetic number, because the mean of its divisors is an integer number (412638270).

Almost surely, 2^1649940863 is an apocalyptic number.

1649940863 is a deficient number, since it is larger than the sum of its proper divisors (612217).

1649940863 is an equidigital number, since it uses as much as digits as its factorization.

1649940863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612216.

The product of its (nonzero) digits is 1119744, while the sum is 50.

The square root of 1649940863 is about 40619.4640905072. The cubic root of 1649940863 is about 1181.6516330933.

The spelling of 1649940863 in words is "one billion, six hundred forty-nine million, nine hundred forty thousand, eight hundred sixty-three".