661057538 has 16 divisors (see below), whose sum is σ = 1065985920. Its totient is φ = 306469296.

The previous prime is 661057493. The next prime is 661057583. The reversal of 661057538 is 835750166.

It is an interprime number because it is at equal distance from previous prime (661057493) and next prime (661057583).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 661057495 and 661057504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 183281 + ... + 186852.

It is an arithmetic number, because the mean of its divisors is an integer number (66624120).

Almost surely, 2^661057538 is an apocalyptic number.

661057538 is a deficient number, since it is larger than the sum of its proper divisors (404928382).

661057538 is a wasteful number, since it uses less digits than its factorization.

661057538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370201.

The product of its (nonzero) digits is 151200, while the sum is 41.

The square root of 661057538 is about 25711.0392244265. The cubic root of 661057538 is about 871.1235486054.

The spelling of 661057538 in words is "six hundred sixty-one million, fifty-seven thousand, five hundred thirty-eight".