20678949 has 16 divisors (see below), whose sum is σ = 30723840. Its totient is φ = 13746240.

The previous prime is 20678923. The next prime is 20678951. The reversal of 20678949 is 94987602.

It is a happy number.

It is not a de Polignac number, because 20678949 - 2¹³ = 20670757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20678149) 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, 10749 + ... + 12525.

It is an arithmetic number, because the mean of its divisors is an integer number (1920240).

Almost surely, 2^20678949 is an apocalyptic number.

It is an amenable number.

20678949 is a deficient number, since it is larger than the sum of its proper divisors (10044891).

20678949 is a wasteful number, since it uses less digits than its factorization.

20678949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2217 (or 2211 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 20678949 is about 4547.4112415747. The cubic root of 20678949 is about 274.4792304152.

The spelling of 20678949 in words is "twenty million, six hundred seventy-eight thousand, nine hundred forty-nine".