77151220 has 12 divisors (see below), whose sum is σ = 162017604. Its totient is φ = 30860480.

The previous prime is 77151211. The next prime is 77151233. The reversal of 77151220 is 2215177.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13853284 + 63297936 = 3722^2 + 7956^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1928761 + ... + 1928800.

It is an arithmetic number, because the mean of its divisors is an integer number (13501467).

Almost surely, 2^77151220 is an apocalyptic number.

It is an amenable number.

77151220 is an abundant number, since it is smaller than the sum of its proper divisors (84866384).

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

77151220 is a wasteful number, since it uses less digits than its factorization.

77151220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3857570 (or 3857568 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 77151220 is about 8783.5767202205. The cubic root of 77151220 is about 425.7104058666.

Adding to 77151220 its reverse (2215177), we get a palindrome (79366397).

The spelling of 77151220 in words is "seventy-seven million, one hundred fifty-one thousand, two hundred twenty".