61132721 has 8 divisors (see below), whose sum is σ = 66038784. Its totient is φ = 56255760.

The previous prime is 61132711. The next prime is 61132733. The reversal of 61132721 is 12723116.

61132721 = 254² + 255² + ... + 584².

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 61132721 - 2⁶ = 61132657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61132711) 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, 2801 + ... + 11406.

It is an arithmetic number, because the mean of its divisors is an integer number (8254848).

Almost surely, 2^61132721 is an apocalyptic number.

It is an amenable number.

61132721 is a deficient number, since it is larger than the sum of its proper divisors (4906063).

61132721 is a wasteful number, since it uses less digits than its factorization.

61132721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14551.

The product of its digits is 504, while the sum is 23.

The square root of 61132721 is about 7818.7416506750. The cubic root of 61132721 is about 393.9350065005.

Adding to 61132721 its reverse (12723116), we get a palindrome (73855837).

The spelling of 61132721 in words is "sixty-one million, one hundred thirty-two thousand, seven hundred twenty-one".