660001620 has 24 divisors (see below), whose sum is σ = 1848004704. Its totient is φ = 176000416.

The previous prime is 660001619. The next prime is 660001627. The reversal of 660001620 is 26100066.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

660001620 is a modest number, since divided by 1620 gives 660 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660001627) 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, 5499954 + ... + 5500073.

It is an arithmetic number, because the mean of its divisors is an integer number (77000196).

Almost surely, 2^660001620 is an apocalyptic number.

660001620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

660001620 is an abundant number, since it is smaller than the sum of its proper divisors (1188003084).

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

660001620 is a wasteful number, since it uses less digits than its factorization.

660001620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11000039 (or 11000037 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 660001620 is about 25690.4966865181. The cubic root of 660001620 is about 870.6594814740.

Adding to 660001620 its reverse (26100066), we get a palindrome (686101686).

The spelling of 660001620 in words is "six hundred sixty million, one thousand, six hundred twenty".