1561670643877 has 8 divisors (see below), whose sum is σ = 1644221989760. Its totient is φ = 1479155113440.

The previous prime is 1561670643857. The next prime is 1561670643889. The reversal of 1561670643877 is 7783460761651.

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

It is a cyclic number.

It is not a de Polignac number, because 1561670643877 - 2¹⁹ = 1561670119589 is a prime.

It is a super-2 number, since 2×1561670643877² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561670643847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8864328 + ... + 9038785.

It is an arithmetic number, because the mean of its divisors is an integer number (205527748720).

Almost surely, 2^{1561670643877} is an apocalyptic number.

It is an amenable number.

1561670643877 is a deficient number, since it is larger than the sum of its proper divisors (82551345883).

1561670643877 is a wasteful number, since it uses less digits than its factorization.

1561670643877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17907723.

The product of its (nonzero) digits is 35562240, while the sum is 61.

The spelling of 1561670643877 in words is "one trillion, five hundred sixty-one billion, six hundred seventy million, six hundred forty-three thousand, eight hundred seventy-seven".