21376361 has 12 divisors (see below), whose sum is σ = 23670612. Its totient is φ = 19236096.

The previous prime is 21376357. The next prime is 21376403. The reversal of 21376361 is 16367312.

It can be written as a sum of positive squares in 2 ways, for example, as 12709225 + 8667136 = 3565^2 + 2944^2 .

It is not a de Polignac number, because 21376361 - 2² = 21376357 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21376301) 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, 7805 + ... + 10181.

It is an arithmetic number, because the mean of its divisors is an integer number (1972551).

Almost surely, 2^21376361 is an apocalyptic number.

It is an amenable number.

21376361 is a deficient number, since it is larger than the sum of its proper divisors (2294251).

21376361 is a wasteful number, since it uses less digits than its factorization.

21376361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440 (or 2417 counting only the distinct ones).

The product of its digits is 4536, while the sum is 29.

The square root of 21376361 is about 4623.4576887866. The cubic root of 21376361 is about 277.5308452578.

The spelling of 21376361 in words is "twenty-one million, three hundred seventy-six thousand, three hundred sixty-one".