81214279 has 2 divisors, whose sum is σ = 81214280. Its totient is φ = 81214278.

The previous prime is 81214213. The next prime is 81214283. The reversal of 81214279 is 97241218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81214279 - 2⁹ = 81213767 is a prime.

It is a super-2 number, since 2×81214279² = 13191518226979682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81214579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40607139 + 40607140.

It is an arithmetic number, because the mean of its divisors is an integer number (40607140).

Almost surely, 2^81214279 is an apocalyptic number.

81214279 is a deficient number, since it is larger than the sum of its proper divisors (1).

81214279 is an equidigital number, since it uses as much as digits as its factorization.

81214279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 34.

The square root of 81214279 is about 9011.8965262591. The cubic root of 81214279 is about 433.0560706955.

The spelling of 81214279 in words is "eighty-one million, two hundred fourteen thousand, two hundred seventy-nine".