215451645 has 16 divisors (see below), whose sum is σ = 348598080. Its totient is φ = 113615744.

The previous prime is 215451641. The next prime is 215451661. The reversal of 215451645 is 546154512.

It is a cyclic number.

It is not a de Polignac number, because 215451645 - 2² = 215451641 is a prime.

It is a super-2 number, since 2×215451645² = 92838822666412050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215451641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79359 + ... + 82028.

It is an arithmetic number, because the mean of its divisors is an integer number (21787380).

Almost surely, 2^215451645 is an apocalyptic number.

It is an amenable number.

215451645 is a deficient number, since it is larger than the sum of its proper divisors (133146435).

215451645 is a wasteful number, since it uses less digits than its factorization.

215451645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161484.

The product of its digits is 24000, while the sum is 33.

The square root of 215451645 is about 14678.2711856676. The cubic root of 215451645 is about 599.4918336219.

The spelling of 215451645 in words is "two hundred fifteen million, four hundred fifty-one thousand, six hundred forty-five".