21143007 has 24 divisors (see below), whose sum is σ = 31299840. Its totient is φ = 13749840.

The previous prime is 21142981. The next prime is 21143009. The reversal of 21143007 is 70034112.

It is not a de Polignac number, because 21143007 - 2¹² = 21138911 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93028 + ... + 93254.

It is an arithmetic number, because the mean of its divisors is an integer number (1304160).

Almost surely, 2^21143007 is an apocalyptic number.

21143007 is a deficient number, since it is larger than the sum of its proper divisors (10156833).

21143007 is a wasteful number, since it uses less digits than its factorization.

21143007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21143007 is about 4598.1525638021. The cubic root of 21143007 is about 276.5172640559.

Adding to 21143007 its reverse (70034112), we get a palindrome (91177119).

The spelling of 21143007 in words is "twenty-one million, one hundred forty-three thousand, seven".