78378563961 has 6 divisors (see below), whose sum is σ = 113213481290. Its totient is φ = 52252375968.

The previous prime is 78378563899. The next prime is 78378564023. The reversal of 78378563961 is 16936587387.

78378563961 is a `hidden beast` number, since 7 + 8 + 3 + 7 + 8 + 563 + 9 + 61 = 666.

It is an interprime number because it is at equal distance from previous prime (78378563899) and next prime (78378564023).

It can be written as a sum of positive squares in only one way, i.e., 78377601600 + 962361 = 279960^2 + 981^2 .

It is not a de Polignac number, because 78378563961 - 2⁷ = 78378563833 is a prime.

It is a super-2 number, since 2×78378563961² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78378564961) 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, 4354364656 + ... + 4354364673.

Almost surely, 2^78378563961 is an apocalyptic number.

It is an amenable number.

78378563961 is a deficient number, since it is larger than the sum of its proper divisors (34834917329).

78378563961 is a wasteful number, since it uses less digits than its factorization.

78378563961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8708729335 (or 8708729332 counting only the distinct ones).

The product of its digits is 45722880, while the sum is 63.

The spelling of 78378563961 in words is "seventy-eight billion, three hundred seventy-eight million, five hundred sixty-three thousand, nine hundred sixty-one".