661502090 has 8 divisors (see below), whose sum is σ = 1190703780. Its totient is φ = 264600832.

The previous prime is 661502089. The next prime is 661502131. The reversal of 661502090 is 90205166.

It can be written as a sum of positive squares in 2 ways, for example, as 649689121 + 11812969 = 25489^2 + 3437^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33075095 + ... + 33075114.

Almost surely, 2^661502090 is an apocalyptic number.

661502090 is a deficient number, since it is larger than the sum of its proper divisors (529201690).

661502090 is a wasteful number, since it uses less digits than its factorization.

661502090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66150216.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 661502090 is about 25719.6829296164. The cubic root of 661502090 is about 871.3187776725.

The spelling of 661502090 in words is "six hundred sixty-one million, five hundred two thousand, ninety".