661539147 has 8 divisors (see below), whose sum is σ = 900819456. Its totient is φ = 431642472.

The previous prime is 661539143. The next prime is 661539157. The reversal of 661539147 is 741935166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661539147 - 2² = 661539143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661539099 and 661539108.

It is not an unprimeable number, because it can be changed into a prime (661539143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2345743 + ... + 2346024.

It is an arithmetic number, because the mean of its divisors is an integer number (112602432).

Almost surely, 2^661539147 is an apocalyptic number.

661539147 is a deficient number, since it is larger than the sum of its proper divisors (239280309).

661539147 is a wasteful number, since it uses less digits than its factorization.

661539147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4691817.

The product of its digits is 136080, while the sum is 42.

The square root of 661539147 is about 25720.4033210990. The cubic root of 661539147 is about 871.3350476422.

The spelling of 661539147 in words is "six hundred sixty-one million, five hundred thirty-nine thousand, one hundred forty-seven".