8001211561 has 16 divisors (see below), whose sum is σ = 9267581440. Its totient is φ = 6765819840.

The previous prime is 8001211553. The next prime is 8001211571. The reversal of 8001211561 is 1651121008.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 8001211561 - 2³ = 8001211553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8001211571) 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, 758455 + ... + 768931.

It is an arithmetic number, because the mean of its divisors is an integer number (579223840).

Almost surely, 2^8001211561 is an apocalyptic number.

It is an amenable number.

8001211561 is a deficient number, since it is larger than the sum of its proper divisors (1266369879).

8001211561 is a wasteful number, since it uses less digits than its factorization.

8001211561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11944.

The product of its (nonzero) digits is 480, while the sum is 25.

The square root of 8001211561 is about 89449.4916754701. The cubic root of 8001211561 is about 2000.1009583203.

Adding to 8001211561 its reverse (1651121008), we get a palindrome (9652332569).

The spelling of 8001211561 in words is "eight billion, one million, two hundred eleven thousand, five hundred sixty-one".