77972501 has 4 divisors (see below), whose sum is σ = 78122112. Its totient is φ = 77822892.

The previous prime is 77972497. The next prime is 77972509. The reversal of 77972501 is 10527977.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10527977 = 2551 ⋅4127.

It is a cyclic number.

It is not a de Polignac number, because 77972501 - 2² = 77972497 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77972509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74021 + ... + 75066.

It is an arithmetic number, because the mean of its divisors is an integer number (19530528).

Almost surely, 2^77972501 is an apocalyptic number.

It is an amenable number.

77972501 is a deficient number, since it is larger than the sum of its proper divisors (149611).

77972501 is a wasteful number, since it uses less digits than its factorization.

77972501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149610.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 77972501 is about 8830.2039047805. The cubic root of 77972501 is about 427.2156512248.

The spelling of 77972501 in words is "seventy-seven million, nine hundred seventy-two thousand, five hundred one".