21153206061251 has 8 divisors (see below), whose sum is σ = 23076304874544. Its totient is φ = 19230120594720.

The previous prime is 21153206061223. The next prime is 21153206061289. The reversal of 21153206061251 is 15216060235112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21153206061251 - 2³⁴ = 21136026192067 is a prime.

It is a super-3 number, since 3×21153206061251³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21153206063251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134165 + ... + 6505721.

It is an arithmetic number, because the mean of its divisors is an integer number (2884538109318).

Almost surely, 2^{21153206061251} is an apocalyptic number.

21153206061251 is a deficient number, since it is larger than the sum of its proper divisors (1923098813293).

21153206061251 is a wasteful number, since it uses less digits than its factorization.

21153206061251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6673381.

The product of its (nonzero) digits is 21600, while the sum is 35.

Adding to 21153206061251 its reverse (15216060235112), we get a palindrome (36369266296363).

The spelling of 21153206061251 in words is "twenty-one trillion, one hundred fifty-three billion, two hundred six million, sixty-one thousand, two hundred fifty-one".