1657649138 has 8 divisors (see below), whose sum is σ = 2503161900. Its totient is φ = 823261840.

The previous prime is 1657649117. The next prime is 1657649171. The reversal of 1657649138 is 8319467561.

It can be written as a sum of positive squares in 2 ways, for example, as 1373962489 + 283686649 = 37067^2 + 16843^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2780993 + ... + 2781588.

Almost surely, 2^1657649138 is an apocalyptic number.

1657649138 is a deficient number, since it is larger than the sum of its proper divisors (845512762).

1657649138 is a wasteful number, since it uses less digits than its factorization.

1657649138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5562732.

The product of its digits is 1088640, while the sum is 50.

The square root of 1657649138 is about 40714.2375343073. The cubic root of 1657649138 is about 1183.4889409510.

The spelling of 1657649138 in words is "one billion, six hundred fifty-seven million, six hundred forty-nine thousand, one hundred thirty-eight".