215045761 has 6 divisors (see below), whose sum is σ = 250155330. Its totient is φ = 184324896.

The previous prime is 215045731. The next prime is 215045771. The reversal of 215045761 is 167540512.

It can be written as a sum of positive squares in only one way, i.e., 178382736 + 36663025 = 13356^2 + 6055^2 .

It is not a de Polignac number, because 215045761 - 2¹³ = 215037569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215045731) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2194296 + ... + 2194393.

It is an arithmetic number, because the mean of its divisors is an integer number (41692555).

Almost surely, 2^215045761 is an apocalyptic number.

It is an amenable number.

215045761 is a deficient number, since it is larger than the sum of its proper divisors (35109569).

215045761 is an equidigital number, since it uses as much as digits as its factorization.

215045761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4388703 (or 4388696 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 215045761 is about 14664.4386527409. The cubic root of 215045761 is about 599.1151410529.

The spelling of 215045761 in words is "two hundred fifteen million, forty-five thousand, seven hundred sixty-one".