78291957249 has 81 divisors (see below), whose sum is σ = 127290645027. Its totient is φ = 46336039200.

The previous prime is 78291957241. The next prime is 78291957277. The reversal of 78291957249 is 94275919287.

The square root of 78291957249 is 279807.

It is a perfect power (a square), and thus also a powerful number.

78291957249 is a `hidden beast` number, since 7 + 8 + 2 + 9 + 19 + 572 + 49 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2545908849 + 75746048400 = 50457^2 + 275220^2 .

It is not a de Polignac number, because 78291957249 - 2³ = 78291957241 is a prime.

It is a super-2 number, since 2×78291957249² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78291957241) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 563251422 + ... + 563251560.

Almost surely, 2^78291957249 is an apocalyptic number.

78291957249 is the 279807-th square number.

78291957249 is the 139904-th centered octagonal number.

It is an amenable number.

78291957249 is a deficient number, since it is larger than the sum of its proper divisors (48998687778).

78291957249 is a wasteful number, since it uses less digits than its factorization.

78291957249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 214 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 63.

The spelling of 78291957249 in words is "seventy-eight billion, two hundred ninety-one million, nine hundred fifty-seven thousand, two hundred forty-nine".