661930471 has 2 divisors, whose sum is σ = 661930472. Its totient is φ = 661930470.

The previous prime is 661930463. The next prime is 661930523. The reversal of 661930471 is 174039166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661930471 - 2³ = 661930463 is a prime.

It is a super-3 number, since 3×661930471³ (a number of 27 digits) contains 333 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661930471.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661930571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330965235 + 330965236.

It is an arithmetic number, because the mean of its divisors is an integer number (330965236).

Almost surely, 2^661930471 is an apocalyptic number.

661930471 is a deficient number, since it is larger than the sum of its proper divisors (1).

661930471 is an equidigital number, since it uses as much as digits as its factorization.

661930471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 661930471 is about 25728.0094643950. The cubic root of 661930471 is about 871.5068223623.

The spelling of 661930471 in words is "six hundred sixty-one million, nine hundred thirty thousand, four hundred seventy-one".