21554322025 has 12 divisors (see below), whose sum is σ = 26865849052. Its totient is φ = 17154109440.

The previous prime is 21554321993. The next prime is 21554322047. The reversal of 21554322025 is 52022345512.

It can be written as a sum of positive squares in 6 ways, for example, as 8779369 + 21545542656 = 2963^2 + 146784^2 .

It is not a de Polignac number, because 21554322025 - 2⁵ = 21554321993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2228784 + ... + 2238433.

Almost surely, 2^21554322025 is an apocalyptic number.

21554322025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21554322025 is a deficient number, since it is larger than the sum of its proper divisors (5311527027).

21554322025 is a wasteful number, since it uses less digits than its factorization.

21554322025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4467420 (or 4467415 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 31.

Adding to 21554322025 its reverse (52022345512), we get a palindrome (73576667537).

The spelling of 21554322025 in words is "twenty-one billion, five hundred fifty-four million, three hundred twenty-two thousand, twenty-five".