15780949 has 2 divisors, whose sum is σ = 15780950. Its totient is φ = 15780948.

The previous prime is 15780937. The next prime is 15780983. The reversal of 15780949 is 94908751.

15780949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14938225 + 842724 = 3865^2 + 918^2 .

It is a cyclic number.

It is not a de Polignac number, because 15780949 - 2⁵ = 15780917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15780049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7890474 + 7890475.

It is an arithmetic number, because the mean of its divisors is an integer number (7890475).

Almost surely, 2^15780949 is an apocalyptic number.

It is an amenable number.

15780949 is a deficient number, since it is larger than the sum of its proper divisors (1).

15780949 is an equidigital number, since it uses as much as digits as its factorization.

15780949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 15780949 is about 3972.5242604671. The cubic root of 15780949 is about 250.8289761559.

The spelling of 15780949 in words is "fifteen million, seven hundred eighty thousand, nine hundred forty-nine".