61156139 has 4 divisors (see below), whose sum is σ = 66715800. Its totient is φ = 55596480.

The previous prime is 61156129. The next prime is 61156163. The reversal of 61156139 is 93165116.

It is a happy number.

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 61156139 - 2²⁴ = 44378923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61156129) 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, 2779814 + ... + 2779835.

It is an arithmetic number, because the mean of its divisors is an integer number (16678950).

Almost surely, 2^61156139 is an apocalyptic number.

61156139 is a deficient number, since it is larger than the sum of its proper divisors (5559661).

61156139 is a wasteful number, since it uses less digits than its factorization.

61156139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5559660.

The product of its digits is 4860, while the sum is 32.

The square root of 61156139 is about 7820.2390628420. The cubic root of 61156139 is about 393.9853014005.

The spelling of 61156139 in words is "sixty-one million, one hundred fifty-six thousand, one hundred thirty-nine".