21770379 has 12 divisors (see below), whose sum is σ = 31800600. Its totient is φ = 14349984.

The previous prime is 21770363. The next prime is 21770407. The reversal of 21770379 is 97307712.

21770379 is a `hidden beast` number, since 217 + 70 + 379 = 666.

It is not a de Polignac number, because 21770379 - 2⁴ = 21770363 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770179) 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, 12789 + ... + 14390.

It is an arithmetic number, because the mean of its divisors is an integer number (2650050).

Almost surely, 2^21770379 is an apocalyptic number.

21770379 is a deficient number, since it is larger than the sum of its proper divisors (10030221).

21770379 is a wasteful number, since it uses less digits than its factorization.

21770379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27274 (or 27271 counting only the distinct ones).

The product of its (nonzero) digits is 18522, while the sum is 36.

The square root of 21770379 is about 4665.8738731346. The cubic root of 21770379 is about 279.2256624209.

The spelling of 21770379 in words is "twenty-one million, seven hundred seventy thousand, three hundred seventy-nine".