661615111001 has 8 divisors (see below), whose sum is σ = 723143038464. Its totient is φ = 601606391760.

The previous prime is 661615110973. The next prime is 661615111009. The reversal of 661615111001 is 100111516166.

It is a happy number.

661615111001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 661615111001 - 2³⁸ = 386737204057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661615111009) 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, 379801145 + ... + 379802886.

It is an arithmetic number, because the mean of its divisors is an integer number (90392879808).

Almost surely, 2^661615111001 is an apocalyptic number.

It is an amenable number.

661615111001 is a deficient number, since it is larger than the sum of its proper divisors (61527927463).

661615111001 is a wasteful number, since it uses less digits than its factorization.

661615111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759604111.

The product of its (nonzero) digits is 1080, while the sum is 29.

Adding to 661615111001 its reverse (100111516166), we get a palindrome (761726627167).

The spelling of 661615111001 in words is "six hundred sixty-one billion, six hundred fifteen million, one hundred eleven thousand, one".