21380470 has 16 divisors (see below), whose sum is σ = 38918880. Its totient is φ = 8455744.

The previous prime is 21380467. The next prime is 21380473. The reversal of 21380470 is 7408312.

It is an interprime number because it is at equal distance from previous prime (21380467) and next prime (21380473).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21380473) 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, 11122 + ... + 12901.

It is an arithmetic number, because the mean of its divisors is an integer number (2432430).

Almost surely, 2^21380470 is an apocalyptic number.

21380470 is a deficient number, since it is larger than the sum of its proper divisors (17538410).

21380470 is a wasteful number, since it uses less digits than its factorization.

21380470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24119.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21380470 is about 4623.9020318342. The cubic root of 21380470 is about 277.5486266002.

Adding to 21380470 its reverse (7408312), we get a palindrome (28788782).

The spelling of 21380470 in words is "twenty-one million, three hundred eighty thousand, four hundred seventy".