661237538 has 8 divisors (see below), whose sum is σ = 1068152988. Its totient is φ = 305186544.

The previous prime is 661237523. The next prime is 661237541. The reversal of 661237538 is 835732166.

It can be written as a sum of positive squares in 2 ways, for example, as 649383289 + 11854249 = 25483^2 + 3443^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 661237495 and 661237504.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12716081 + ... + 12716132.

Almost surely, 2^661237538 is an apocalyptic number.

661237538 is a deficient number, since it is larger than the sum of its proper divisors (406915450).

661237538 is a wasteful number, since it uses less digits than its factorization.

661237538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25432228.

The product of its digits is 181440, while the sum is 41.

The square root of 661237538 is about 25714.5394281134. The cubic root of 661237538 is about 871.2026077896.

The spelling of 661237538 in words is "six hundred sixty-one million, two hundred thirty-seven thousand, five hundred thirty-eight".