78199501 has 2 divisors, whose sum is σ = 78199502. Its totient is φ = 78199500.

The previous prime is 78199481. The next prime is 78199531. The reversal of 78199501 is 10599187.

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., 56100100 + 22099401 = 7490^2 + 4701^2 .

It is an emirp because it is prime and its reverse (10599187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78199501 - 2⁵ = 78199469 is a prime.

It is a super-2 number, since 2×78199501² = 12230323913298002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78199531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39099750 + 39099751.

It is an arithmetic number, because the mean of its divisors is an integer number (39099751).

Almost surely, 2^78199501 is an apocalyptic number.

It is an amenable number.

78199501 is a deficient number, since it is larger than the sum of its proper divisors (1).

78199501 is an equidigital number, since it uses as much as digits as its factorization.

78199501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 78199501 is about 8843.0481735655. The cubic root of 78199501 is about 427.6298314098.

The spelling of 78199501 in words is "seventy-eight million, one hundred ninety-nine thousand, five hundred one".