20415394 has 4 divisors (see below), whose sum is σ = 30623094. Its totient is φ = 10207696.

The previous prime is 20415389. The next prime is 20415397. The reversal of 20415394 is 49351402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49351402 = 2 ⋅24675701.

It can be written as a sum of positive squares in only one way, i.e., 19918369 + 497025 = 4463^2 + 705^2 .

It is not an unprimeable number, because it can be changed into a prime (20415397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5103847 + ... + 5103850.

Almost surely, 2^20415394 is an apocalyptic number.

20415394 is a deficient number, since it is larger than the sum of its proper divisors (10207700).

20415394 is a wasteful number, since it uses less digits than its factorization.

20415394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10207699.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20415394 is about 4518.3397393290. The cubic root of 20415394 is about 273.3081538706.

Adding to 20415394 its reverse (49351402), we get a palindrome (69766796).

The spelling of 20415394 in words is "twenty million, four hundred fifteen thousand, three hundred ninety-four".