61641511 has 4 divisors (see below), whose sum is σ = 61670752. Its totient is φ = 61612272.

The previous prime is 61641499. The next prime is 61641521. The reversal of 61641511 is 11514616.

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 61641511 - 2⁵ = 61641479 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 (61641521) 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, 11190 + ... + 15763.

It is an arithmetic number, because the mean of its divisors is an integer number (15417688).

Almost surely, 2^61641511 is an apocalyptic number.

61641511 is a deficient number, since it is larger than the sum of its proper divisors (29241).

61641511 is a wasteful number, since it uses less digits than its factorization.

61641511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29240.

The product of its digits is 720, while the sum is 25.

The square root of 61641511 is about 7851.2107983419. The cubic root of 61641511 is about 395.0248576997.

The spelling of 61641511 in words is "sixty-one million, six hundred forty-one thousand, five hundred eleven".