118280278561 has 27 divisors (see below), whose sum is σ = 130662738801. Its totient is φ = 107046852264.

The previous prime is 118280278559. The next prime is 118280278591. The reversal of 118280278561 is 165872082811.

It is a happy number.

The square root of 118280278561 is 343919.

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

It is not a de Polignac number, because 118280278561 - 2¹ = 118280278559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118280278511) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 150292210 + ... + 150292996.

Almost surely, 2^118280278561 is an apocalyptic number.

118280278561 is the 343919-th square number.

118280278561 is the 171960-th centered octagonal number.

It is an amenable number.

118280278561 is a deficient number, since it is larger than the sum of its proper divisors (12382460240).

118280278561 is an frugal number, since it uses more digits than its factorization.

118280278561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658 (or 829 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 49.

Multiplying 118280278561 by its sum of digits (49), we get a square (5795733649489 = 2407433²).

The spelling of 118280278561 in words is "one hundred eighteen billion, two hundred eighty million, two hundred seventy-eight thousand, five hundred sixty-one".