661353131 has 2 divisors, whose sum is σ = 661353132. Its totient is φ = 661353130.

The previous prime is 661353127. The next prime is 661353191. The reversal of 661353131 is 131353166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661353131 - 2² = 661353127 is a prime.

It is a super-2 number, since 2×661353131² = 874775927767006322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 661353094 and 661353103.

It is not a weakly prime, because it can be changed into another prime (661353191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330676565 + 330676566.

It is an arithmetic number, because the mean of its divisors is an integer number (330676566).

Almost surely, 2^661353131 is an apocalyptic number.

661353131 is a deficient number, since it is larger than the sum of its proper divisors (1).

661353131 is an equidigital number, since it uses as much as digits as its factorization.

661353131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860, while the sum is 29.

The square root of 661353131 is about 25716.7869493839. The cubic root of 661353131 is about 871.2533707150.

The spelling of 661353131 in words is "six hundred sixty-one million, three hundred fifty-three thousand, one hundred thirty-one".