1649557642 has 8 divisors (see below), whose sum is σ = 2559658500. Its totient is φ = 796338144.

The previous prime is 1649557627. The next prime is 1649557649. The reversal of 1649557642 is 2467559461.

It can be written as a sum of positive squares in 2 ways, for example, as 1634665761 + 14891881 = 40431^2 + 3859^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1649557649) 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, 14220267 + ... + 14220382.

Almost surely, 2^1649557642 is an apocalyptic number.

1649557642 is a deficient number, since it is larger than the sum of its proper divisors (910100858).

1649557642 is a wasteful number, since it uses less digits than its factorization.

1649557642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28440680.

The product of its digits is 1814400, while the sum is 49.

The square root of 1649557642 is about 40614.7466076055. The cubic root of 1649557642 is about 1181.5601411709.

The spelling of 1649557642 in words is "one billion, six hundred forty-nine million, five hundred fifty-seven thousand, six hundred forty-two".