20983988 has 6 divisors (see below), whose sum is σ = 36721986. Its totient is φ = 10491992.

The previous prime is 20983969. The next prime is 20983997. The reversal of 20983988 is 88938902.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19166884 + 1817104 = 4378^2 + 1348^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2622995 + ... + 2623002.

It is an arithmetic number, because the mean of its divisors is an integer number (6120331).

Almost surely, 2^20983988 is an apocalyptic number.

It is an amenable number.

20983988 is a deficient number, since it is larger than the sum of its proper divisors (15737998).

20983988 is a wasteful number, since it uses less digits than its factorization.

20983988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5246001 (or 5245999 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 20983988 is about 4580.8283093781. The cubic root of 20983988 is about 275.8222793423.

The spelling of 20983988 in words is "twenty million, nine hundred eighty-three thousand, nine hundred eighty-eight".