661744770 has 16 divisors (see below), whose sum is σ = 1588187520. Its totient is φ = 176465264.

The previous prime is 661744763. The next prime is 661744793. The reversal of 661744770 is 77447166.

It is a super-2 number, since 2×661744770² = 875812281244705800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11029050 + ... + 11029109.

It is an arithmetic number, because the mean of its divisors is an integer number (99261720).

Almost surely, 2^661744770 is an apocalyptic number.

661744770 is an abundant number, since it is smaller than the sum of its proper divisors (926442750).

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

661744770 is a wasteful number, since it uses less digits than its factorization.

661744770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22058169.

The product of its (nonzero) digits is 197568, while the sum is 42.

The square root of 661744770 is about 25724.4002845547. The cubic root of 661744770 is about 871.4253159039.

The spelling of 661744770 in words is "six hundred sixty-one million, seven hundred forty-four thousand, seven hundred seventy".