1661254420 has 48 divisors (see below), whose sum is σ = 4031838720. Its totient is φ = 563169024.

The previous prime is 1661254411. The next prime is 1661254447. The reversal of 1661254420 is 244521661.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 54204 + ... + 79123.

It is an arithmetic number, because the mean of its divisors is an integer number (83996640).

Almost surely, 2^1661254420 is an apocalyptic number.

1661254420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661254420 is an abundant number, since it is smaller than the sum of its proper divisors (2370584300).

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

1661254420 is a wasteful number, since it uses less digits than its factorization.

1661254420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133432 (or 133430 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1661254420 is about 40758.4889317551. The cubic root of 1661254420 is about 1184.3463241897.

The spelling of 1661254420 in words is "one billion, six hundred sixty-one million, two hundred fifty-four thousand, four hundred twenty".