661047057057 has 4 divisors (see below), whose sum is σ = 881396076080. Its totient is φ = 440698038036.

The previous prime is 661047057031. The next prime is 661047057091. The reversal of 661047057057 is 750750740166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 661047057057 - 2¹² = 661047052961 is a prime.

It is a super-2 number, since 2×661047057057² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661047056997 and 661047057015.

It is not an unprimeable number, because it can be changed into a prime (661047057257) 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, 110174509507 + ... + 110174509512.

It is an arithmetic number, because the mean of its divisors is an integer number (220349019020).

Almost surely, 2^661047057057 is an apocalyptic number.

It is an amenable number.

661047057057 is a deficient number, since it is larger than the sum of its proper divisors (220349019023).

661047057057 is a wasteful number, since it uses less digits than its factorization.

661047057057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220349019022.

The product of its (nonzero) digits is 1234800, while the sum is 48.

The spelling of 661047057057 in words is "six hundred sixty-one billion, forty-seven million, fifty-seven thousand, fifty-seven".