21512423032425 has 144 divisors (see below), whose sum is σ = 41740851258288. Its totient is φ = 10528048742400.

The previous prime is 21512423032391. The next prime is 21512423032459. The reversal of 21512423032425 is 52423032421512.

21512423032425 is a `hidden beast` number, since 2 + 1 + 512 + 42 + 30 + 32 + 42 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21512423032391) and next prime (21512423032459).

It can be written as a sum of positive squares in 24 ways, for example, as 20234774862864 + 1277648169561 = 4498308^2 + 1130331^2 .

It is not a de Polignac number, because 21512423032425 - 2¹⁵ = 21512422999657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21512423032425.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1660799749 + ... + 1660812701.

It is an arithmetic number, because the mean of its divisors is an integer number (289867022627).

Almost surely, 2^{21512423032425} is an apocalyptic number.

21512423032425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21512423032425 is a deficient number, since it is larger than the sum of its proper divisors (20228428225863).

21512423032425 is a wasteful number, since it uses less digits than its factorization.

21512423032425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16300 (or 16292 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

Adding to 21512423032425 its reverse (52423032421512), we get a palindrome (73935455453937).

The spelling of 21512423032425 in words is "twenty-one trillion, five hundred twelve billion, four hundred twenty-three million, thirty-two thousand, four hundred twenty-five".