661025131 has 8 divisors (see below), whose sum is σ = 713530944. Its totient is φ = 608756160.

The previous prime is 661025117. The next prime is 661025179. The reversal of 661025131 is 131520166.

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 661025131 - 2¹⁹ = 660500843 is a prime.

It is a super-2 number, since 2×661025131² = 873908447627134322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661025096 and 661025105.

It is not an unprimeable number, because it can be changed into a prime (661023131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53386 + ... + 64591.

It is an arithmetic number, because the mean of its divisors is an integer number (89191368).

Almost surely, 2^661025131 is an apocalyptic number.

661025131 is a deficient number, since it is larger than the sum of its proper divisors (52505813).

661025131 is a wasteful number, since it uses less digits than its factorization.

661025131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118421.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 661025131 is about 25710.4090010252. The cubic root of 661025131 is about 871.1093133533.

Adding to 661025131 its reverse (131520166), we get a palindrome (792545297).

The spelling of 661025131 in words is "six hundred sixty-one million, twenty-five thousand, one hundred thirty-one".