1544221656 has 192 divisors, whose sum is σ = 4865702400. Its totient is φ = 438856704.

The previous prime is 1544221579. The next prime is 1544221681. The reversal of 1544221656 is 6561224451.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1544221656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 533445 + ... + 536331.

It is an arithmetic number, because the mean of its divisors is an integer number (25342200).

Almost surely, 2^1544221656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1544221656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2432851200).

1544221656 is an abundant number, since it is smaller than the sum of its proper divisors (3321480744).

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

1544221656 is a wasteful number, since it uses less digits than its factorization.

1544221656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2958 (or 2951 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 1544221656 is about 39296.5858058941. The cubic root of 1544221656 is about 1155.8546190740.

The spelling of 1544221656 in words is "one billion, five hundred forty-four million, two hundred twenty-one thousand, six hundred fifty-six".