21990049 has 8 divisors (see below), whose sum is σ = 23474880. Its totient is φ = 20538000.

The previous prime is 21990043. The next prime is 21990079. The reversal of 21990049 is 94009912.

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

It is a cyclic number.

It is not a de Polignac number, because 21990049 - 2³ = 21990041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21989996 and 21990023.

It is not an unprimeable number, because it can be changed into a prime (21990041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6802 + ... + 9499.

It is an arithmetic number, because the mean of its divisors is an integer number (2934360).

Almost surely, 2^21990049 is an apocalyptic number.

It is an amenable number.

21990049 is a deficient number, since it is larger than the sum of its proper divisors (1484831).

21990049 is a wasteful number, since it uses less digits than its factorization.

21990049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16391.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 21990049 is about 4689.3548596795. The cubic root of 21990049 is about 280.1616795830.

The spelling of 21990049 in words is "twenty-one million, nine hundred ninety thousand, forty-nine".