661028501 has 8 divisors (see below), whose sum is σ = 755766144. Its totient is φ = 566367120.

The previous prime is 661028497. The next prime is 661028549. The reversal of 661028501 is 105820166.

It is a happy number.

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 661028501 - 2² = 661028497 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661028101) 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, 911 + ... + 36371.

It is an arithmetic number, because the mean of its divisors is an integer number (94470768).

Almost surely, 2^661028501 is an apocalyptic number.

It is an amenable number.

661028501 is a deficient number, since it is larger than the sum of its proper divisors (94737643).

661028501 is a wasteful number, since it uses less digits than its factorization.

661028501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38131.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 661028501 is about 25710.4745386000. The cubic root of 661028501 is about 871.1107936971.

Adding to 661028501 its reverse (105820166), we get a palindrome (766848667).

The spelling of 661028501 in words is "six hundred sixty-one million, twenty-eight thousand, five hundred one".