20697390 has 128 divisors (see below), whose sum is σ = 64696320. Its totient is φ = 4610304.

The previous prime is 20697389. The next prime is 20697421. The reversal of 20697390 is 9379602.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 88714 + ... + 88946.

It is an arithmetic number, because the mean of its divisors is an integer number (505440).

Almost surely, 2^20697390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20697390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32348160).

20697390 is an abundant number, since it is smaller than the sum of its proper divisors (43998930).

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

20697390 is a wasteful number, since it uses less digits than its factorization.

20697390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20697390 is about 4549.4384268830. The cubic root of 20697390 is about 274.5607975459.

The spelling of 20697390 in words is "twenty million, six hundred ninety-seven thousand, three hundred ninety".