21121552025 has 24 divisors (see below), whose sum is σ = 30017138304. Its totient is φ = 14442278400.

The previous prime is 21121552019. The next prime is 21121552031. The reversal of 21121552025 is 52025512112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21121552019) and next prime (21121552031).

It is not a de Polignac number, because 21121552025 - 2²⁴ = 21104774809 is a prime.

It is a super-2 number, since 2×21121552025² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21121551985 and 21121552003.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109181 + ... + 232730.

It is an arithmetic number, because the mean of its divisors is an integer number (1250714096).

Almost surely, 2^21121552025 is an apocalyptic number.

21121552025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21121552025 is a deficient number, since it is larger than the sum of its proper divisors (8895586279).

21121552025 is a wasteful number, since it uses less digits than its factorization.

21121552025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342281 (or 342276 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 26.

The spelling of 21121552025 in words is "twenty-one billion, one hundred twenty-one million, five hundred fifty-two thousand, twenty-five".