1883978601561 has 45 divisors (see below), whose sum is σ = 3273972497829. Its totient is φ = 1076509787976.

The previous prime is 1883978601541. The next prime is 1883978601677. The reversal of 1883978601561 is 1651068793881.

The square root of 1883978601561 is 1372581.

It is a perfect power (a square), and thus also a powerful number.

1883978601561 is a `hidden beast` number, since 1 + 8 + 8 + 3 + 9 + 7 + 8 + 60 + 1 + 561 = 666.

It is not a de Polignac number, because 1883978601561 - 2⁷ = 1883978601433 is a prime.

It is a super-2 number, since 2×1883978601561² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (1883978601511) by changing a digit.

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 44 ways as a sum of consecutive naturals, for example, 86461710 + ... + 86483496.

Almost surely, 2^{1883978601561} is an apocalyptic number.

1883978601561 is the 1372581-st square number.

1883978601561 is the 686291-st centered octagonal number.

It is an amenable number.

1883978601561 is a deficient number, since it is larger than the sum of its proper divisors (1389993896268).

1883978601561 is an frugal number, since it uses more digits than its factorization.

1883978601561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43600 (or 21797 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 63.

The spelling of 1883978601561 in words is "one trillion, eight hundred eighty-three billion, nine hundred seventy-eight million, six hundred one thousand, five hundred sixty-one".