61581911 has 8 divisors (see below), whose sum is σ = 62966640. Its totient is φ = 60211008.

The previous prime is 61581893. The next prime is 61581913. The reversal of 61581911 is 11918516.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61581911 - 2¹⁰ = 61580887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61581913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5825 + ... + 12533.

It is an arithmetic number, because the mean of its divisors is an integer number (7870830).

Almost surely, 2^61581911 is an apocalyptic number.

61581911 is a deficient number, since it is larger than the sum of its proper divisors (1384729).

61581911 is a wasteful number, since it uses less digits than its factorization.

61581911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6913.

The product of its digits is 2160, while the sum is 32.

The square root of 61581911 is about 7847.4142875217. The cubic root of 61581911 is about 394.8975026477.

The spelling of 61581911 in words is "sixty-one million, five hundred eighty-one thousand, nine hundred eleven".