1649768421 has 16 divisors (see below), whose sum is σ = 2527100928. Its totient is φ = 937786800.

The previous prime is 1649768413. The next prime is 1649768431. The reversal of 1649768421 is 1248679461.

It is not a de Polignac number, because 1649768421 - 2³ = 1649768413 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1649768411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201645 + ... + 209666.

It is an arithmetic number, because the mean of its divisors is an integer number (157943808).

Almost surely, 2^1649768421 is an apocalyptic number.

It is an amenable number.

1649768421 is a deficient number, since it is larger than the sum of its proper divisors (877332507).

1649768421 is a wasteful number, since it uses less digits than its factorization.

1649768421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411512.

The product of its digits is 580608, while the sum is 48.

The square root of 1649768421 is about 40617.3413827148. The cubic root of 1649768421 is about 1181.6104652602.

The spelling of 1649768421 in words is "one billion, six hundred forty-nine million, seven hundred sixty-eight thousand, four hundred twenty-one".