61115539 has 4 divisors (see below), whose sum is σ = 63087040. Its totient is φ = 59144040.

The previous prime is 61115521. The next prime is 61115567. The reversal of 61115539 is 93551116.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61115539 - 2⁹ = 61115027 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 1971469 = 61115539 / (6 + 1 + 1 + 1 + 5 + 5 + 3 + 9).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61115539.

It is not an unprimeable number, because it can be changed into a prime (61115239) 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, 985704 + ... + 985765.

It is an arithmetic number, because the mean of its divisors is an integer number (15771760).

Almost surely, 2^61115539 is an apocalyptic number.

61115539 is a deficient number, since it is larger than the sum of its proper divisors (1971501).

61115539 is a wasteful number, since it uses less digits than its factorization.

61115539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971500.

The product of its digits is 4050, while the sum is 31.

The square root of 61115539 is about 7817.6428033007. The cubic root of 61115539 is about 393.8980965042.

It can be divided in two parts, 61 and 115539, that added together give a square (115600 = 340²).

The spelling of 61115539 in words is "sixty-one million, one hundred fifteen thousand, five hundred thirty-nine".