661783722 has 16 divisors (see below), whose sum is σ = 1366263552. Its totient is φ = 213478560.

The previous prime is 661783673. The next prime is 661783729. The reversal of 661783722 is 227387166.

It is not an unprimeable number, because it can be changed into a prime (661783729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1778803 + ... + 1779174.

It is an arithmetic number, because the mean of its divisors is an integer number (85391472).

Almost surely, 2^661783722 is an apocalyptic number.

661783722 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

661783722 is an abundant number, since it is smaller than the sum of its proper divisors (704479830).

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

661783722 is a wasteful number, since it uses less digits than its factorization.

661783722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3558013.

The product of its digits is 169344, while the sum is 42.

The square root of 661783722 is about 25725.1573756119. The cubic root of 661783722 is about 871.4424136806.

The spelling of 661783722 in words is "six hundred sixty-one million, seven hundred eighty-three thousand, seven hundred twenty-two".