70778621 has 2 divisors, whose sum is σ = 70778622. Its totient is φ = 70778620.

The previous prime is 70778563. The next prime is 70778627. The reversal of 70778621 is 12687707.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51681721 + 19096900 = 7189^2 + 4370^2 .

It is a cyclic number.

It is not a de Polignac number, because 70778621 - 2⁶ = 70778557 is a prime.

It is a super-2 number, since 2×70778621² = 10019226381323282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70778627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35389310 + 35389311.

It is an arithmetic number, because the mean of its divisors is an integer number (35389311).

Almost surely, 2^70778621 is an apocalyptic number.

It is an amenable number.

70778621 is a deficient number, since it is larger than the sum of its proper divisors (1).

70778621 is an equidigital number, since it uses as much as digits as its factorization.

70778621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 70778621 is about 8413.0030904547. The cubic root of 70778621 is about 413.6509559295.

The spelling of 70778621 in words is "seventy million, seven hundred seventy-eight thousand, six hundred twenty-one".