21143390 has 32 divisors (see below), whose sum is σ = 40309920. Its totient is φ = 7962624.

The previous prime is 21143383. The next prime is 21143411. The reversal of 21143390 is 9334112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48614 + ... + 49046.

It is an arithmetic number, because the mean of its divisors is an integer number (1259685).

Almost surely, 2^21143390 is an apocalyptic number.

21143390 is a deficient number, since it is larger than the sum of its proper divisors (19166530).

21143390 is a wasteful number, since it uses less digits than its factorization.

21143390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21143390 is about 4598.1942107745. The cubic root of 21143390 is about 276.5189337250.

The spelling of 21143390 in words is "twenty-one million, one hundred forty-three thousand, three hundred ninety".