20151493 has 2 divisors, whose sum is σ = 20151494. Its totient is φ = 20151492.

The previous prime is 20151479. The next prime is 20151497. The reversal of 20151493 is 39415102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19873764 + 277729 = 4458^2 + 527^2 .

It is a cyclic number.

It is not a de Polignac number, because 20151493 - 2¹³ = 20143301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20151497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10075746 + 10075747.

It is an arithmetic number, because the mean of its divisors is an integer number (10075747).

Almost surely, 2^20151493 is an apocalyptic number.

It is an amenable number.

20151493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20151493 is an equidigital number, since it uses as much as digits as its factorization.

20151493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20151493 is about 4489.0414344267. The cubic root of 20151493 is about 272.1253972339.

Adding to 20151493 its reverse (39415102), we get a palindrome (59566595).

The spelling of 20151493 in words is "twenty million, one hundred fifty-one thousand, four hundred ninety-three".