21377147 has 16 divisors (see below), whose sum is σ = 25401600. Its totient is φ = 17771040.

The previous prime is 21377131. The next prime is 21377159. The reversal of 21377147 is 74177312.

It is a cyclic number.

It is not a de Polignac number, because 21377147 - 2⁴ = 21377131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21377947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4298 + ... + 7824.

It is an arithmetic number, because the mean of its divisors is an integer number (1587600).

Almost surely, 2^21377147 is an apocalyptic number.

21377147 is a deficient number, since it is larger than the sum of its proper divisors (4024453).

21377147 is a wasteful number, since it uses less digits than its factorization.

21377147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3586.

The product of its digits is 8232, while the sum is 32.

The square root of 21377147 is about 4623.5426893238. The cubic root of 21377147 is about 277.5342467811.

The spelling of 21377147 in words is "twenty-one million, three hundred seventy-seven thousand, one hundred forty-seven".