61451561 has 8 divisors (see below), whose sum is σ = 65857344. Its totient is φ = 57190320.

The previous prime is 61451557. The next prime is 61451573. The reversal of 61451561 is 16515416.

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 61451561 - 2² = 61451557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61451521) 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, 35255 + ... + 36956.

It is an arithmetic number, because the mean of its divisors is an integer number (8232168).

Almost surely, 2^61451561 is an apocalyptic number.

It is an amenable number.

61451561 is a deficient number, since it is larger than the sum of its proper divisors (4405783).

61451561 is a wasteful number, since it uses less digits than its factorization.

61451561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72271.

The product of its digits is 3600, while the sum is 29.

The square root of 61451561 is about 7839.1046044813. The cubic root of 61451561 is about 394.6186802346.

Adding to 61451561 its reverse (16515416), we get a palindrome (77966977).

The spelling of 61451561 in words is "sixty-one million, four hundred fifty-one thousand, five hundred sixty-one".