661350090 has 64 divisors (see below), whose sum is σ = 1649071872. Its totient is φ = 169612800.

The previous prime is 661350083. The next prime is 661350103. The reversal of 661350090 is 90053166.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 83544 + ... + 91116.

It is an arithmetic number, because the mean of its divisors is an integer number (25766748).

Almost surely, 2^661350090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661350090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (824535936).

661350090 is an abundant number, since it is smaller than the sum of its proper divisors (987721782).

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

661350090 is a wasteful number, since it uses less digits than its factorization.

661350090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7695.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 661350090 is about 25716.7278245114. The cubic root of 661350090 is about 871.2520353287.

The spelling of 661350090 in words is "six hundred sixty-one million, three hundred fifty thousand, ninety".