21253410115 has 32 divisors (see below), whose sum is σ = 30879926784. Its totient is φ = 13708561920.

The previous prime is 21253410091. The next prime is 21253410131. The reversal of 21253410115 is 51101435212.

It is not a de Polignac number, because 21253410115 - 2⁷ = 21253409987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21253410115.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1125300 + ... + 1144030.

It is an arithmetic number, because the mean of its divisors is an integer number (964997712).

Almost surely, 2^21253410115 is an apocalyptic number.

21253410115 is a deficient number, since it is larger than the sum of its proper divisors (9626516669).

21253410115 is a wasteful number, since it uses less digits than its factorization.

21253410115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20667.

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

Adding to 21253410115 its reverse (51101435212), we get a palindrome (72354845327).

The spelling of 21253410115 in words is "twenty-one billion, two hundred fifty-three million, four hundred ten thousand, one hundred fifteen".