61513251 has 4 divisors (see below), whose sum is σ = 82017672. Its totient is φ = 41008832.

The previous prime is 61513219. The next prime is 61513261. The reversal of 61513251 is 15231516.

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 61513251 - 2⁵ = 61513219 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61513211) 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, 10252206 + ... + 10252211.

It is an arithmetic number, because the mean of its divisors is an integer number (20504418).

Almost surely, 2^61513251 is an apocalyptic number.

61513251 is a deficient number, since it is larger than the sum of its proper divisors (20504421).

61513251 is a wasteful number, since it uses less digits than its factorization.

61513251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20504420.

The product of its digits is 900, while the sum is 24.

The square root of 61513251 is about 7843.0383780777. The cubic root of 61513251 is about 394.7506860202.

Adding to 61513251 its reverse (15231516), we get a palindrome (76744767).

The spelling of 61513251 in words is "sixty-one million, five hundred thirteen thousand, two hundred fifty-one".