1977691872 has 288 divisors, whose sum is σ = 6179828256. Its totient is φ = 548536320.

The previous prime is 1977691853. The next prime is 1977691909. The reversal of 1977691872 is 2781967791.

1977691872 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×1977691872² = 7822530281149728768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20388528 + ... + 20388624.

It is an arithmetic number, because the mean of its divisors is an integer number (21457737).

Almost surely, 2^1977691872 is an apocalyptic number.

1977691872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1977691872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3089914128).

1977691872 is an abundant number, since it is smaller than the sum of its proper divisors (4202136384).

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

1977691872 is a wasteful number, since it uses less digits than its factorization.

1977691872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 163 counting only the distinct ones).

The product of its digits is 2667168, while the sum is 57.

The square root of 1977691872 is about 44471.2477000590. The cubic root of 1977691872 is about 1255.2191110687.

The spelling of 1977691872 in words is "one billion, nine hundred seventy-seven million, six hundred ninety-one thousand, eight hundred seventy-two".