77949780 has 96 divisors (see below), whose sum is σ = 232364160. Its totient is φ = 19468800.

The previous prime is 77949769. The next prime is 77949791. The reversal of 77949780 is 8794977.

It is an interprime number because it is at equal distance from previous prime (77949769) and next prime (77949791).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 114802 + ... + 115478.

It is an arithmetic number, because the mean of its divisors is an integer number (2420460).

Almost surely, 2^77949780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77949780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116182080).

77949780 is an abundant number, since it is smaller than the sum of its proper divisors (154414380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77949780 is a wasteful number, since it uses less digits than its factorization.

77949780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809 (or 807 counting only the distinct ones).

The product of its (nonzero) digits is 889056, while the sum is 51.

The square root of 77949780 is about 8828.9172609103. The cubic root of 77949780 is about 427.1741506544.

The spelling of 77949780 in words is "seventy-seven million, nine hundred forty-nine thousand, seven hundred eighty".