1788021225 has 27 divisors (see below), whose sum is σ = 3203681143. Its totient is φ = 953273040.

The previous prime is 1788021167. The next prime is 1788021233. The reversal of 1788021225 is 5221208871.

The square root of 1788021225 is 42285.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 643687641 + 1144333584 = 25371^2 + 33828^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1788021225 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1788021225.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 632866 + ... + 635684.

Almost surely, 2^1788021225 is an apocalyptic number.

1788021225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1788021225 is the 42285-th square number.

1788021225 is the 21143-rd centered octagonal number.

It is an amenable number.

1788021225 is a deficient number, since it is larger than the sum of its proper divisors (1415659918).

1788021225 is an frugal number, since it uses more digits than its factorization.

1788021225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5654 (or 2827 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The cubic root of 1788021225 is about 1213.7359714032.

Multiplying 1788021225 by its sum of digits (36), we get a square (64368764100 = 253710²).

The spelling of 1788021225 in words is "one billion, seven hundred eighty-eight million, twenty-one thousand, two hundred twenty-five".