661057620 has 24 divisors (see below), whose sum is σ = 1850961504. Its totient is φ = 176282016.

The previous prime is 661057613. The next prime is 661057627. The reversal of 661057620 is 26750166.

661057620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (661057613) and next prime (661057627).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661057627) 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, 5508754 + ... + 5508873.

It is an arithmetic number, because the mean of its divisors is an integer number (77123396).

Almost surely, 2^661057620 is an apocalyptic number.

661057620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661057620 is an abundant number, since it is smaller than the sum of its proper divisors (1189903884).

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

661057620 is a wasteful number, since it uses less digits than its factorization.

661057620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11017639 (or 11017637 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 661057620 is about 25711.0408190723. The cubic root of 661057620 is about 871.1235846245.

The spelling of 661057620 in words is "six hundred sixty-one million, fifty-seven thousand, six hundred twenty".