10001561555 has 8 divisors (see below), whose sum is σ = 12153796800. Its totient is φ = 7899967296.

The previous prime is 10001561551. The next prime is 10001561573. The reversal of 10001561555 is 55516510001.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10001561555 - 2² = 10001561551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (10001561551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12659810 + ... + 12660599.

It is an arithmetic number, because the mean of its divisors is an integer number (1519224600).

Almost surely, 2^10001561555 is an apocalyptic number.

10001561555 is a deficient number, since it is larger than the sum of its proper divisors (2152235245).

10001561555 is an equidigital number, since it uses as much as digits as its factorization.

10001561555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25320493.

The product of its (nonzero) digits is 3750, while the sum is 29.

The spelling of 10001561555 in words is "ten billion, one million, five hundred sixty-one thousand, five hundred fifty-five".