21503101102225 has 12 divisors (see below), whose sum is σ = 28067205649840. Its totient is φ = 16297087150800.

The previous prime is 21503101102199. The next prime is 21503101102277. The reversal of 21503101102225 is 52220110130512.

It is a happy number.

It is not a de Polignac number, because 21503101102225 - 2¹⁷ = 21503100971153 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 21503101102225.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22634842791 + ... + 22634843740.

Almost surely, 2^{21503101102225} is an apocalyptic number.

21503101102225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21503101102225 is a deficient number, since it is larger than the sum of its proper divisors (6564104547615).

21503101102225 is a wasteful number, since it uses less digits than its factorization.

21503101102225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45269686560 (or 45269686555 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 21503101102225 its reverse (52220110130512), we get a palindrome (73723211232737).

The spelling of 21503101102225 in words is "twenty-one trillion, five hundred three billion, one hundred one million, one hundred two thousand, two hundred twenty-five".