77870389 has 8 divisors (see below), whose sum is σ = 78767640. Its totient is φ = 76978176.

The previous prime is 77870381. The next prime is 77870407. The reversal of 77870389 is 98307877.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3186225 + 74684164 = 1785^2 + 8642^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77870389 - 2³ = 77870381 is a prime.

It is a super-2 number, since 2×77870389² = 12127594966022642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77870381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35797 + ... + 37909.

It is an arithmetic number, because the mean of its divisors is an integer number (9845955).

Almost surely, 2^77870389 is an apocalyptic number.

It is an amenable number.

77870389 is a deficient number, since it is larger than the sum of its proper divisors (897251).

77870389 is a wasteful number, since it uses less digits than its factorization.

77870389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2519.

The product of its (nonzero) digits is 592704, while the sum is 49.

The square root of 77870389 is about 8824.4200376002. The cubic root of 77870389 is about 427.0290773216.

The spelling of 77870389 in words is "seventy-seven million, eight hundred seventy thousand, three hundred eighty-nine".