661700064 has 48 divisors (see below), whose sum is σ = 1812488832. Its totient is φ = 210976128.

The previous prime is 661700063. The next prime is 661700113. The reversal of 661700064 is 460007166.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661700063) 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, 147634 + ... + 152049.

It is an arithmetic number, because the mean of its divisors is an integer number (37760184).

Almost surely, 2^661700064 is an apocalyptic number.

It is an amenable number.

661700064 is an abundant number, since it is smaller than the sum of its proper divisors (1150788768).

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

661700064 is a wasteful number, since it uses less digits than its factorization.

661700064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299719 (or 299711 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 661700064 is about 25723.5313283383. The cubic root of 661700064 is about 871.4056916121.

The spelling of 661700064 in words is "six hundred sixty-one million, seven hundred thousand, sixty-four".