21123702 has 12 divisors (see below), whose sum is σ = 45768060. Its totient is φ = 7041228.

The previous prime is 21123701. The next prime is 21123709. The reversal of 21123702 is 20732112.

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1173539 = 21123702 / (2 + 1 + 1 + 2 + 3 + 7 + 0 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 586752 + ... + 586787.

It is an arithmetic number, because the mean of its divisors is an integer number (3814005).

Almost surely, 2^21123702 is an apocalyptic number.

21123702 is an abundant number, since it is smaller than the sum of its proper divisors (24644358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21123702 is a wasteful number, since it uses less digits than its factorization.

21123702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173547 (or 1173544 counting only the distinct ones).

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

The square root of 21123702 is about 4596.0528717585. The cubic root of 21123702 is about 276.4330787536.

Adding to 21123702 its reverse (20732112), we get a palindrome (41855814).

The spelling of 21123702 in words is "twenty-one million, one hundred twenty-three thousand, seven hundred two".