661142980 has 24 divisors (see below), whose sum is σ = 1396721088. Its totient is φ = 262872288.

The previous prime is 661142959. The next prime is 661142987. The reversal of 661142980 is 89241166.

It is a happy number.

661142980 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×661142980² = 874220080006560800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661142987) 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, 95634 + ... + 102313.

It is an arithmetic number, because the mean of its divisors is an integer number (58196712).

Almost surely, 2^661142980 is an apocalyptic number.

It is an amenable number.

661142980 is an abundant number, since it is smaller than the sum of its proper divisors (735578108).

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

661142980 is a wasteful number, since it uses less digits than its factorization.

661142980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198123 (or 198121 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 661142980 is about 25712.7007527409. The cubic root of 661142980 is about 871.1610780323.

It can be divided in two parts, 661 and 142980, that added together give a square (143641 = 379²).

The spelling of 661142980 in words is "six hundred sixty-one million, one hundred forty-two thousand, nine hundred eighty".