661775802 has 8 divisors (see below), whose sum is σ = 1323551616. Its totient is φ = 220591932.

The previous prime is 661775773. The next prime is 661775809. The reversal of 661775802 is 208577166.

It is a sphenic number, since it is the product of 3 distinct primes.

661775802 is an admirable number.

It is a super-2 number, since 2×661775802² = 875894424225486408, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661775809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55147978 + ... + 55147989.

It is an arithmetic number, because the mean of its divisors is an integer number (165443952).

Almost surely, 2^661775802 is an apocalyptic number.

661775802 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

661775802 is a wasteful number, since it uses less digits than its factorization.

661775802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110295972.

The product of its (nonzero) digits is 141120, while the sum is 42.

The square root of 661775802 is about 25725.0034402330. The cubic root of 661775802 is about 871.4389372924.

The spelling of 661775802 in words is "six hundred sixty-one million, seven hundred seventy-five thousand, eight hundred two".