77561401 has 8 divisors (see below), whose sum is σ = 81915680. Its totient is φ = 73234368.

The previous prime is 77561387. The next prime is 77561441. The reversal of 77561401 is 10416577.

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 77561401 - 2¹⁹ = 77037113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77561441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 816 + ... + 12481.

It is an arithmetic number, because the mean of its divisors is an integer number (10239460).

Almost surely, 2^77561401 is an apocalyptic number.

It is an amenable number.

77561401 is a deficient number, since it is larger than the sum of its proper divisors (4354279).

77561401 is a wasteful number, since it uses less digits than its factorization.

77561401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13623.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 77561401 is about 8806.8950828314. The cubic root of 77561401 is about 426.4635146016.

Adding to 77561401 its reverse (10416577), we get a palindrome (87977978).

The spelling of 77561401 in words is "seventy-seven million, five hundred sixty-one thousand, four hundred one".