661631354 has 8 divisors (see below), whose sum is σ = 993968820. Its totient is φ = 330308416.

The previous prime is 661631353. The next prime is 661631393. The reversal of 661631354 is 453136166.

It can be written as a sum of positive squares in 2 ways, for example, as 624750025 + 36881329 = 24995^2 + 6073^2 .

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

It is not an unprimeable number, because it can be changed into a prime (661631353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251999 + ... + 254610.

Almost surely, 2^661631354 is an apocalyptic number.

661631354 is a deficient number, since it is larger than the sum of its proper divisors (332337466).

661631354 is a wasteful number, since it uses less digits than its factorization.

661631354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507264.

The product of its digits is 38880, while the sum is 35.

The square root of 661631354 is about 25722.1957460867. The cubic root of 661631354 is about 871.3755287226.

The spelling of 661631354 in words is "six hundred sixty-one million, six hundred thirty-one thousand, three hundred fifty-four".