77491970 has 8 divisors (see below), whose sum is σ = 139485564. Its totient is φ = 30996784.

The previous prime is 77491963. The next prime is 77491979. The reversal of 77491970 is 7919477.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 73599241 + 3892729 = 8579^2 + 1973^2 .

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

It is not an unprimeable number, because it can be changed into a prime (77491979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3874589 + ... + 3874608.

Almost surely, 2^77491970 is an apocalyptic number.

77491970 is a deficient number, since it is larger than the sum of its proper divisors (61993594).

77491970 is a wasteful number, since it uses less digits than its factorization.

77491970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7749204.

The product of its (nonzero) digits is 111132, while the sum is 44.

The square root of 77491970 is about 8802.9523456622. The cubic root of 77491970 is about 426.3362235023.

The spelling of 77491970 in words is "seventy-seven million, four hundred ninety-one thousand, nine hundred seventy".