21377770 has 16 divisors (see below), whose sum is σ = 38568960. Its totient is φ = 8531344.

The previous prime is 21377767. The next prime is 21377771. The reversal of 21377770 is 7777312.

It is not an unprimeable number, because it can be changed into a prime (21377771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2559 + ... + 7021.

It is an arithmetic number, because the mean of its divisors is an integer number (2410560).

Almost surely, 2^21377770 is an apocalyptic number.

21377770 is a deficient number, since it is larger than the sum of its proper divisors (17191190).

21377770 is a wasteful number, since it uses less digits than its factorization.

21377770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4949.

The product of its (nonzero) digits is 14406, while the sum is 34.

The square root of 21377770 is about 4623.6100614131. The cubic root of 21377770 is about 277.5369428402.

The spelling of 21377770 in words is "twenty-one million, three hundred seventy-seven thousand, seven hundred seventy".