21798402 has 32 divisors (see below), whose sum is σ = 45144000. Its totient is φ = 7011648.

The previous prime is 21798389. The next prime is 21798409. The reversal of 21798402 is 20489712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21798409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32749 + ... + 33407.

It is an arithmetic number, because the mean of its divisors is an integer number (1410750).

Almost surely, 2^21798402 is an apocalyptic number.

21798402 is an abundant number, since it is smaller than the sum of its proper divisors (23345598).

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

21798402 is a wasteful number, since it uses less digits than its factorization.

21798402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21798402 is about 4668.8758818371. The cubic root of 21798402 is about 279.3454181952.

The spelling of 21798402 in words is "twenty-one million, seven hundred ninety-eight thousand, four hundred two".