1661661254 has 8 divisors (see below), whose sum is σ = 2719082088. Its totient is φ = 755300560.

The previous prime is 1661661223. The next prime is 1661661263. The reversal of 1661661254 is 4521661661.

It is a happy number.

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

It is a super-2 number, since 2×1661661254² = 5522236246089705032, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37765007 + ... + 37765050.

It is an arithmetic number, because the mean of its divisors is an integer number (339885261).

Almost surely, 2^1661661254 is an apocalyptic number.

1661661254 is a deficient number, since it is larger than the sum of its proper divisors (1057420834).

1661661254 is a wasteful number, since it uses less digits than its factorization.

1661661254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75530070.

The product of its digits is 51840, while the sum is 38.

The square root of 1661661254 is about 40763.4794147899. The cubic root of 1661661254 is about 1184.4429967241.

The spelling of 1661661254 in words is "one billion, six hundred sixty-one million, six hundred sixty-one thousand, two hundred fifty-four".