15494821 has 2 divisors, whose sum is σ = 15494822. Its totient is φ = 15494820.

The previous prime is 15494813. The next prime is 15494849. The reversal of 15494821 is 12849451.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14737921 + 756900 = 3839^2 + 870^2 .

It is an emirp because it is prime and its reverse (12849451) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15494821 - 2³ = 15494813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15494891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7747410 + 7747411.

It is an arithmetic number, because the mean of its divisors is an integer number (7747411).

Almost surely, 2^15494821 is an apocalyptic number.

It is an amenable number.

15494821 is a deficient number, since it is larger than the sum of its proper divisors (1).

15494821 is an equidigital number, since it uses as much as digits as its factorization.

15494821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 15494821 is about 3936.3461483970. The cubic root of 15494821 is about 249.3037748822.

The spelling of 15494821 in words is "fifteen million, four hundred ninety-four thousand, eight hundred twenty-one".