61535721 has 8 divisors (see below), whose sum is σ = 88359040. Its totient is φ = 37868112.

The previous prime is 61535687. The next prime is 61535729. The reversal of 61535721 is 12753516.

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

It is not a de Polignac number, because 61535721 - 2¹¹ = 61533673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61535729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 788881 + ... + 788958.

It is an arithmetic number, because the mean of its divisors is an integer number (11044880).

Almost surely, 2^61535721 is an apocalyptic number.

It is an amenable number.

61535721 is a deficient number, since it is larger than the sum of its proper divisors (26823319).

61535721 is a wasteful number, since it uses less digits than its factorization.

61535721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1577855.

The product of its digits is 6300, while the sum is 30.

The square root of 61535721 is about 7844.4707278439. The cubic root of 61535721 is about 394.7987459528.

The spelling of 61535721 in words is "sixty-one million, five hundred thirty-five thousand, seven hundred twenty-one".