356216561 has 4 divisors (see below), whose sum is σ = 356267124. Its totient is φ = 356166000.

The previous prime is 356216513. The next prime is 356216563. The reversal of 356216561 is 165612653.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165612653 = 41 ⋅4039333.

It can be written as a sum of positive squares in 2 ways, for example, as 287641600 + 68574961 = 16960^2 + 8281^2 .

It is a cyclic number.

It is not a de Polignac number, because 356216561 - 2¹⁰ = 356215537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (356216563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12590 + ... + 29511.

It is an arithmetic number, because the mean of its divisors is an integer number (89066781).

Almost surely, 2^356216561 is an apocalyptic number.

It is an amenable number.

356216561 is a deficient number, since it is larger than the sum of its proper divisors (50563).

356216561 is an equidigital number, since it uses as much as digits as its factorization.

356216561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50562.

The product of its digits is 32400, while the sum is 35.

The square root of 356216561 is about 18873.7002466395. The cubic root of 356216561 is about 708.8777887858.

The spelling of 356216561 in words is "three hundred fifty-six million, two hundred sixteen thousand, five hundred sixty-one".