21949402 has 8 divisors (see below), whose sum is σ = 32951700. Its totient is φ = 10965504.

The previous prime is 21949387. The next prime is 21949409. The reversal of 21949402 is 20494912.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20151121 + 1798281 = 4489^2 + 1341^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21949409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1077 + ... + 6712.

Almost surely, 2^21949402 is an apocalyptic number.

21949402 is a deficient number, since it is larger than the sum of its proper divisors (11002298).

21949402 is a wasteful number, since it uses less digits than its factorization.

21949402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9200.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21949402 is about 4685.0188900366. The cubic root of 21949402 is about 279.9889536458.

The spelling of 21949402 in words is "twenty-one million, nine hundred forty-nine thousand, four hundred two".