661736340 has 36 divisors (see below), whose sum is σ = 2007267444. Its totient is φ = 176462976.

The previous prime is 661736333. The next prime is 661736363. The reversal of 661736340 is 43637166.

It is a happy number.

661736340 is a `hidden beast` number, since 6 + 6 + 17 + 3 + 634 + 0 = 666.

661736340 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 167029776 + 494706564 = 12924^2 + 22242^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 661736295 and 661736304.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1837977 + ... + 1838336.

It is an arithmetic number, because the mean of its divisors is an integer number (55757429).

Almost surely, 2^661736340 is an apocalyptic number.

661736340 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661736340 is an abundant number, since it is smaller than the sum of its proper divisors (1345531104).

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

661736340 is a wasteful number, since it uses less digits than its factorization.

661736340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3676328 (or 3676323 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 661736340 is about 25724.2364318166. The cubic root of 661736340 is about 871.4216155112.

The spelling of 661736340 in words is "six hundred sixty-one million, seven hundred thirty-six thousand, three hundred forty".