21402044 has 6 divisors (see below), whose sum is σ = 37453584. Its totient is φ = 10701020.

The previous prime is 21402023. The next prime is 21402047. The reversal of 21402044 is 44020412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2675252 + ... + 2675259.

It is an arithmetic number, because the mean of its divisors is an integer number (6242264).

Almost surely, 2^21402044 is an apocalyptic number.

It is an amenable number.

21402044 is a deficient number, since it is larger than the sum of its proper divisors (16051540).

21402044 is a wasteful number, since it uses less digits than its factorization.

21402044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5350515 (or 5350513 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 21402044 is about 4626.2343217784. The cubic root of 21402044 is about 277.6419488578.

Adding to 21402044 its reverse (44020412), we get a palindrome (65422456).

The spelling of 21402044 in words is "twenty-one million, four hundred two thousand, forty-four".