1977609906 has 12 divisors (see below), whose sum is σ = 4284821502. Its totient is φ = 659203296.

The previous prime is 1977609901. The next prime is 1977609911. The reversal of 1977609906 is 6099067791.

It is an interprime number because it is at equal distance from previous prime (1977609901) and next prime (1977609911).

It can be written as a sum of positive squares in only one way, i.e., 1970560881 + 7049025 = 44391^2 + 2655^2 .

It is not an unprimeable number, because it can be changed into a prime (1977609901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54933591 + ... + 54933626.

Almost surely, 2^1977609906 is an apocalyptic number.

1977609906 is an abundant number, since it is smaller than the sum of its proper divisors (2307211596).

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

1977609906 is a wasteful number, since it uses less digits than its factorization.

1977609906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109867225 (or 109867222 counting only the distinct ones).

The product of its (nonzero) digits is 1285956, while the sum is 54.

The square root of 1977609906 is about 44470.3261287794. The cubic root of 1977609906 is about 1255.2017698586.

The spelling of 1977609906 in words is "one billion, nine hundred seventy-seven million, six hundred nine thousand, nine hundred six".