1861562800881 has 63 divisors (see below), whose sum is σ = 3247201697481. Its totient is φ = 1063602817704.

The previous prime is 1861562800859. The next prime is 1861562800901. The reversal of 1861562800881 is 1880082651681.

The square root of 1861562800881 is 1364391.

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

1861562800881 is a `hidden beast` number, since 1 + 8 + 6 + 1 + 5 + 628 + 0 + 0 + 8 + 8 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (63).

It is not a de Polignac number, because 1861562800881 - 2¹³ = 1861562792689 is a prime.

It is a super-2 number, since 2×1861562800881² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1861562800681) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 257866290 + ... + 257873508.

It is an arithmetic number, because the mean of its divisors is an integer number (51542884087).

Almost surely, 2^{1861562800881} is an apocalyptic number.

1861562800881 is the 1364391-st square number.

1861562800881 is the 682196-th centered octagonal number.

It is an amenable number.

1861562800881 is a deficient number, since it is larger than the sum of its proper divisors (1385638896600).

1861562800881 is an frugal number, since it uses more digits than its factorization.

1861562800881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14470 (or 7229 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 54.

The spelling of 1861562800881 in words is "one trillion, eight hundred sixty-one billion, five hundred sixty-two million, eight hundred thousand, eight hundred eighty-one".