661071530 has 64 divisors (see below), whose sum is σ = 1423008000. Its totient is φ = 216319488.

The previous prime is 661071517. The next prime is 661071533. The reversal of 661071530 is 35170166.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a junction number, because it is equal to n+sod(n) for n = 661071493 and 661071502.

It is not an unprimeable number, because it can be changed into a prime (661071533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 178841 + ... + 182499.

It is an arithmetic number, because the mean of its divisors is an integer number (22234500).

Almost surely, 2^661071530 is an apocalyptic number.

661071530 is an abundant number, since it is smaller than the sum of its proper divisors (761936470).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661071530 is a wasteful number, since it uses less digits than its factorization.

661071530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3791.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 661071530 is about 25711.3113240068. The cubic root of 661071530 is about 871.1296946537.

The spelling of 661071530 in words is "six hundred sixty-one million, seventy-one thousand, five hundred thirty".