78402749 has 2 divisors, whose sum is σ = 78402750. Its totient is φ = 78402748.

The previous prime is 78402743. The next prime is 78402761. The reversal of 78402749 is 94720487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45832900 + 32569849 = 6770^2 + 5707^2 .

It is a cyclic number.

It is not a de Polignac number, because 78402749 - 2¹⁶ = 78337213 is a prime.

It is a super-2 number, since 2×78402749² = 12293982101514002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78402743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39201374 + 39201375.

It is an arithmetic number, because the mean of its divisors is an integer number (39201375).

Almost surely, 2^78402749 is an apocalyptic number.

It is an amenable number.

78402749 is a deficient number, since it is larger than the sum of its proper divisors (1).

78402749 is an equidigital number, since it uses as much as digits as its factorization.

78402749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 78402749 is about 8854.5326810623. The cubic root of 78402749 is about 427.9999945410. Note that the first 5 decimals are identical.

The spelling of 78402749 in words is "seventy-eight million, four hundred two thousand, seven hundred forty-nine".