661628390 has 8 divisors (see below), whose sum is σ = 1190931120. Its totient is φ = 264651352.

The previous prime is 661628371. The next prime is 661628399. The reversal of 661628390 is 93826166.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661628399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33081410 + ... + 33081429.

It is an arithmetic number, because the mean of its divisors is an integer number (148866390).

Almost surely, 2^661628390 is an apocalyptic number.

661628390 is a deficient number, since it is larger than the sum of its proper divisors (529302730).

661628390 is a wasteful number, since it uses less digits than its factorization.

661628390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66162846.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 661628390 is about 25722.1381304121. The cubic root of 661628390 is about 871.3742275142.

The spelling of 661628390 in words is "six hundred sixty-one million, six hundred twenty-eight thousand, three hundred ninety".