20947995 has 48 divisors (see below), whose sum is σ = 38918880. Its totient is φ = 10386432.

The previous prime is 20947991. The next prime is 20947999. The reversal of 20947995 is 59974902.

It is an interprime number because it is at equal distance from previous prime (20947991) and next prime (20947999).

It is not a de Polignac number, because 20947995 - 2² = 20947991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 20947995.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20947991) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106237 + ... + 106433.

It is an arithmetic number, because the mean of its divisors is an integer number (810810).

Almost surely, 2^20947995 is an apocalyptic number.

20947995 is a deficient number, since it is larger than the sum of its proper divisors (17970885).

20947995 is a wasteful number, since it uses less digits than its factorization.

20947995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 45.

The square root of 20947995 is about 4576.8979669641. The cubic root of 20947995 is about 275.6644867610.

The spelling of 20947995 in words is "twenty million, nine hundred forty-seven thousand, nine hundred ninety-five".