21152206254615 has 16 divisors (see below), whose sum is σ = 35314987834368. Its totient is φ = 10790690726816.

The previous prime is 21152206254611. The next prime is 21152206254629. The reversal of 21152206254615 is 51645260225112.

It is a cyclic number.

It is not a de Polignac number, because 21152206254615 - 2² = 21152206254611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152206254611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30655371039 + ... + 30655371728.

It is an arithmetic number, because the mean of its divisors is an integer number (2207186739648).

Almost surely, 2^{21152206254615} is an apocalyptic number.

21152206254615 is a deficient number, since it is larger than the sum of its proper divisors (14162781579753).

21152206254615 is a wasteful number, since it uses less digits than its factorization.

21152206254615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61310742798.

The product of its (nonzero) digits is 288000, while the sum is 42.

Adding to 21152206254615 its reverse (51645260225112), we get a palindrome (72797466479727).

The spelling of 21152206254615 in words is "twenty-one trillion, one hundred fifty-two billion, two hundred six million, two hundred fifty-four thousand, six hundred fifteen".