7561020721 has 16 divisors (see below), whose sum is σ = 8089200000. Its totient is φ = 7046683776.

The previous prime is 7561020703. The next prime is 7561020739. The reversal of 7561020721 is 1270201657.

It is an interprime number because it is at equal distance from previous prime (7561020703) and next prime (7561020739).

It is a cyclic number.

It is not a de Polignac number, because 7561020721 - 2¹⁵ = 7560987953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7561020791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 325275 + ... + 347743.

It is an arithmetic number, because the mean of its divisors is an integer number (505575000).

Almost surely, 2^7561020721 is an apocalyptic number.

It is an amenable number.

7561020721 is a deficient number, since it is larger than the sum of its proper divisors (528179279).

7561020721 is a wasteful number, since it uses less digits than its factorization.

7561020721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22776.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 7561020721 is about 86954.1299824223. The cubic root of 7561020721 is about 1962.7281113994.

The spelling of 7561020721 in words is "seven billion, five hundred sixty-one million, twenty thousand, seven hundred twenty-one".