78121453 has 2 divisors, whose sum is σ = 78121454. Its totient is φ = 78121452.

The previous prime is 78121429. The next prime is 78121471. The reversal of 78121453 is 35412187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49252324 + 28869129 = 7018^2 + 5373^2 .

It is a cyclic number.

It is not a de Polignac number, because 78121453 - 2¹³ = 78113261 is a prime.

It is a super-2 number, since 2×78121453² = 12205922837662418, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78121403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39060726 + 39060727.

It is an arithmetic number, because the mean of its divisors is an integer number (39060727).

Almost surely, 2^78121453 is an apocalyptic number.

It is an amenable number.

78121453 is a deficient number, since it is larger than the sum of its proper divisors (1).

78121453 is an equidigital number, since it uses as much as digits as its factorization.

78121453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 31.

The square root of 78121453 is about 8838.6341139341. The cubic root of 78121453 is about 427.4875169343.

The spelling of 78121453 in words is "seventy-eight million, one hundred twenty-one thousand, four hundred fifty-three".