21145055145 has 16 divisors (see below), whose sum is σ = 34009224192. Its totient is φ = 11218317440.

The previous prime is 21145055137. The next prime is 21145055159. The reversal of 21145055145 is 54155054112.

It is a happy number.

It is not a de Polignac number, because 21145055145 - 2³ = 21145055137 is a prime.

It is a super-2 number, since 2×21145055145² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3687372 + ... + 3693101.

It is an arithmetic number, because the mean of its divisors is an integer number (2125576512).

Almost surely, 2^21145055145 is an apocalyptic number.

It is an amenable number.

21145055145 is a deficient number, since it is larger than the sum of its proper divisors (12864169047).

21145055145 is a wasteful number, since it uses less digits than its factorization.

21145055145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7380672.

The product of its (nonzero) digits is 20000, while the sum is 33.

The spelling of 21145055145 in words is "twenty-one billion, one hundred forty-five million, fifty-five thousand, one hundred forty-five".