1649940823 has 2 divisors, whose sum is σ = 1649940824. Its totient is φ = 1649940822.

The previous prime is 1649940779. The next prime is 1649940881. The reversal of 1649940823 is 3280499461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1649940823 - 2²⁵ = 1616386391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1649940883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824970411 + 824970412.

It is an arithmetic number, because the mean of its divisors is an integer number (824970412).

Almost surely, 2^1649940823 is an apocalyptic number.

1649940823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649940823 is an equidigital number, since it uses as much as digits as its factorization.

1649940823 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 1649940823 is about 40619.4635981324. The cubic root of 1649940823 is about 1181.6516235442.

The spelling of 1649940823 in words is "one billion, six hundred forty-nine million, nine hundred forty thousand, eight hundred twenty-three".