1851649738 has 4 divisors (see below), whose sum is σ = 2777474610. Its totient is φ = 925824868.

The previous prime is 1851649727. The next prime is 1851649757. The reversal of 1851649738 is 8379461581.

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

It can be written as a sum of positive squares in only one way, i.e., 1693569409 + 158080329 = 41153^2 + 12573^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 462912433 + ... + 462912436.

Almost surely, 2^1851649738 is an apocalyptic number.

1851649738 is a deficient number, since it is larger than the sum of its proper divisors (925824872).

1851649738 is an equidigital number, since it uses as much as digits as its factorization.

1851649738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925824871.

The product of its digits is 1451520, while the sum is 52.

The square root of 1851649738 is about 43030.7998763676. The cubic root of 1851649738 is about 1227.9658222936.

The spelling of 1851649738 in words is "one billion, eight hundred fifty-one million, six hundred forty-nine thousand, seven hundred thirty-eight".