215031649 has 12 divisors (see below), whose sum is σ = 254243028. Its totient is φ = 181288800.

The previous prime is 215031581. The next prime is 215031667. The reversal of 215031649 is 946130512.

215031649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 18835600 + 196196049 = 4340^2 + 14007^2 .

It is not a de Polignac number, because 215031649 - 2¹¹ = 215029601 is a prime.

It is a super-2 number, since 2×215031649² = 92477220143318402, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215031649.

It is not an unprimeable number, because it can be changed into a prime (215031689) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32982 + ... + 38959.

It is an arithmetic number, because the mean of its divisors is an integer number (21186919).

Almost surely, 2^215031649 is an apocalyptic number.

It is an amenable number.

215031649 is a deficient number, since it is larger than the sum of its proper divisors (39211379).

215031649 is an equidigital number, since it uses as much as digits as its factorization.

215031649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72016 (or 72009 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 215031649 is about 14663.9574808440. The cubic root of 215031649 is about 599.1020354736.

The spelling of 215031649 in words is "two hundred fifteen million, thirty-one thousand, six hundred forty-nine".