7977879401 has 2 divisors, whose sum is σ = 7977879402. Its totient is φ = 7977879400.

The previous prime is 7977879389. The next prime is 7977879421. The reversal of 7977879401 is 1049787797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6616195600 + 1361683801 = 81340^2 + 36901^2 .

It is an emirp because it is prime and its reverse (1049787797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7977879401 - 2²⁶ = 7910770537 is a prime.

It is not a weakly prime, because it can be changed into another prime (7977879421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3988939700 + 3988939701.

It is an arithmetic number, because the mean of its divisors is an integer number (3988939701).

Almost surely, 2^7977879401 is an apocalyptic number.

It is an amenable number.

7977879401 is a deficient number, since it is larger than the sum of its proper divisors (1).

7977879401 is an equidigital number, since it uses as much as digits as its factorization.

7977879401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6223392, while the sum is 59.

The square root of 7977879401 is about 89318.9755930956. The cubic root of 7977879401 is about 1998.1549151043.

The spelling of 7977879401 in words is "seven billion, nine hundred seventy-seven million, eight hundred seventy-nine thousand, four hundred one".