7557616021 has 16 divisors (see below), whose sum is σ = 7858675440. Its totient is φ = 7259374080.

The previous prime is 7557616019. The next prime is 7557616049. The reversal of 7557616021 is 1206167557.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 495062500 + 7062553521 = 22250^2 + 84039^2 .

It is a cyclic number.

It is not a de Polignac number, because 7557616021 - 2¹ = 7557616019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7557616081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6109015 + ... + 6110251.

It is an arithmetic number, because the mean of its divisors is an integer number (491167215).

Almost surely, 2^7557616021 is an apocalyptic number.

It is an amenable number.

7557616021 is a deficient number, since it is larger than the sum of its proper divisors (301059419).

7557616021 is a wasteful number, since it uses less digits than its factorization.

7557616021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184.

The product of its (nonzero) digits is 88200, while the sum is 40.

The square root of 7557616021 is about 86934.5502145148. The cubic root of 7557616021 is about 1962.4334640701.

The spelling of 7557616021 in words is "seven billion, five hundred fifty-seven million, six hundred sixteen thousand, twenty-one".