61265721 has 32 divisors (see below), whose sum is σ = 94804992. Its totient is φ = 34823360.

The previous prime is 61265713. The next prime is 61265741. The reversal of 61265721 is 12756216.

It is not a de Polignac number, because 61265721 - 2³ = 61265713 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61265741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39466 + ... + 40988.

It is an arithmetic number, because the mean of its divisors is an integer number (2962656).

Almost surely, 2^61265721 is an apocalyptic number.

It is an amenable number.

61265721 is a deficient number, since it is larger than the sum of its proper divisors (33539271).

61265721 is a wasteful number, since it uses less digits than its factorization.

61265721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1613.

The product of its digits is 5040, while the sum is 30.

The square root of 61265721 is about 7827.2422346571. The cubic root of 61265721 is about 394.2204804949.

The spelling of 61265721 in words is "sixty-one million, two hundred sixty-five thousand, seven hundred twenty-one".