21402470 has 16 divisors (see below), whose sum is σ = 38579328. Its totient is φ = 8548800.

The previous prime is 21402467. The next prime is 21402481. The reversal of 21402470 is 7420412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9995 + ... + 11945.

It is an arithmetic number, because the mean of its divisors is an integer number (2411208).

Almost surely, 2^21402470 is an apocalyptic number.

21402470 is a deficient number, since it is larger than the sum of its proper divisors (17176858).

21402470 is a wasteful number, since it uses less digits than its factorization.

21402470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3055.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 21402470 is about 4626.2803633157. The cubic root of 21402470 is about 277.6437909667.

Adding to 21402470 its reverse (7420412), we get a palindrome (28822882).

The spelling of 21402470 in words is "twenty-one million, four hundred two thousand, four hundred seventy".