661610401323431 has 8 divisors (see below), whose sum is σ = 756819230853504. Its totient is φ = 566574836271480.

The previous prime is 661610401323371. The next prime is 661610401323437. The reversal of 661610401323431 is 134323104016166.

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 661610401323431 - 2¹⁴ = 661610401307047 is a prime.

It is a super-2 number, since 2×661610401323431² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661610401323437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43316111345 + ... + 43316126618.

It is an arithmetic number, because the mean of its divisors is an integer number (94602403856688).

Almost surely, 2^{661610401323431} is an apocalyptic number.

661610401323431 is a deficient number, since it is larger than the sum of its proper divisors (95208829530073).

661610401323431 is a wasteful number, since it uses less digits than its factorization.

661610401323431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86632239061.

The product of its (nonzero) digits is 186624, while the sum is 41.

Adding to 661610401323431 its reverse (134323104016166), we get a palindrome (795933505339597).

The spelling of 661610401323431 in words is "six hundred sixty-one trillion, six hundred ten billion, four hundred one million, three hundred twenty-three thousand, four hundred thirty-one".