20939958 has 80 divisors (see below), whose sum is σ = 51673776. Its totient is φ = 6298560.

The previous prime is 20939953. The next prime is 20939981. The reversal of 20939958 is 85993902.

20939958 is a `hidden beast` number, since 209 + 399 + 58 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20939951) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 128385 + ... + 128547.

Almost surely, 2^20939958 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20939958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25836888).

20939958 is an abundant number, since it is smaller than the sum of its proper divisors (30733818).

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

20939958 is a wasteful number, since it uses less digits than its factorization.

20939958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 20939958 is about 4576.0198863204. The cubic root of 20939958 is about 275.6292280345.

The spelling of 20939958 in words is "twenty million, nine hundred thirty-nine thousand, nine hundred fifty-eight".