401216117521 has 4 divisors (see below), whose sum is σ = 401885928000. Its totient is φ = 400546307044.

The previous prime is 401216117509. The next prime is 401216117593. The reversal of 401216117521 is 125711612104.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-401216117521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (401216117501) 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, 334904341 + ... + 334905538.

It is an arithmetic number, because the mean of its divisors is an integer number (100471482000).

Almost surely, 2^401216117521 is an apocalyptic number.

It is an amenable number.

401216117521 is a deficient number, since it is larger than the sum of its proper divisors (669810479).

401216117521 is an equidigital number, since it uses as much as digits as its factorization.

401216117521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669810478.

The product of its (nonzero) digits is 3360, while the sum is 31.

Adding to 401216117521 its reverse (125711612104), we get a palindrome (526927729625).

The spelling of 401216117521 in words is "four hundred one billion, two hundred sixteen million, one hundred seventeen thousand, five hundred twenty-one".