661915144752 has 20 divisors (see below), whose sum is σ = 1709947457400. Its totient is φ = 220638381568.

The previous prime is 661915144741. The next prime is 661915144753. The reversal of 661915144752 is 257441519166.

It is a happy number.

It is a super-2 number, since 2×661915144752² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661915144695 and 661915144704.

It is not an unprimeable number, because it can be changed into a prime (661915144753) 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, 6894949377 + ... + 6894949472.

It is an arithmetic number, because the mean of its divisors is an integer number (85497372870).

Almost surely, 2^661915144752 is an apocalyptic number.

It is an amenable number.

661915144752 is an abundant number, since it is smaller than the sum of its proper divisors (1048032312648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661915144752 is a wasteful number, since it uses less digits than its factorization.

661915144752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13789898860 (or 13789898854 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 51.

The spelling of 661915144752 in words is "six hundred sixty-one billion, nine hundred fifteen million, one hundred forty-four thousand, seven hundred fifty-two".