215455381 has 2 divisors, whose sum is σ = 215455382. Its totient is φ = 215455380.

The previous prime is 215455367. The next prime is 215455447. The reversal of 215455381 is 183554512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214036900 + 1418481 = 14630^2 + 1191^2 .

It is a cyclic number.

It is not a de Polignac number, because 215455381 - 2¹¹ = 215453333 is a prime.

It is a super-2 number, since 2×215455381² = 92842042403710322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215455351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107727690 + 107727691.

It is an arithmetic number, because the mean of its divisors is an integer number (107727691).

Almost surely, 2^215455381 is an apocalyptic number.

It is an amenable number.

215455381 is a deficient number, since it is larger than the sum of its proper divisors (1).

215455381 is an equidigital number, since it uses as much as digits as its factorization.

215455381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24000, while the sum is 34.

The square root of 215455381 is about 14678.3984480597. The cubic root of 215455381 is about 599.4952987282.

The spelling of 215455381 in words is "two hundred fifteen million, four hundred fifty-five thousand, three hundred eighty-one".