4072166597521 has 9 divisors (see below), whose sum is σ = 4476042229449. Its totient is φ = 3701949454500.

The previous prime is 4072166597509. The next prime is 4072166597531. The reversal of 4072166597521 is 1257956612704.

The square root of 4072166597521 is 2017961.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-4072166597521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4072166597531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22105846 + ... + 22289296.

Almost surely, 2^{4072166597521} is an apocalyptic number.

4072166597521 is the 2017961-st square number.

4072166597521 is the 1008981-st centered octagonal number.

It is an amenable number.

4072166597521 is a deficient number, since it is larger than the sum of its proper divisors (403875631928).

4072166597521 is an frugal number, since it uses more digits than its factorization.

4072166597521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366924 (or 183462 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 55.

The spelling of 4072166597521 in words is "four trillion, seventy-two billion, one hundred sixty-six million, five hundred ninety-seven thousand, five hundred twenty-one".