121563479391 has 32 divisors (see below), whose sum is σ = 171896211456. Its totient is φ = 76281264000.

The previous prime is 121563479381. The next prime is 121563479441. The reversal of 121563479391 is 193974365121.

It is a happy number.

It is not a de Polignac number, because 121563479391 - 2⁹ = 121563478879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121563479381) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14657956 + ... + 14666246.

It is an arithmetic number, because the mean of its divisors is an integer number (5371756608).

Almost surely, 2^121563479391 is an apocalyptic number.

121563479391 is a deficient number, since it is larger than the sum of its proper divisors (50332732065).

121563479391 is a wasteful number, since it uses less digits than its factorization.

121563479391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12623.

The product of its digits is 1224720, while the sum is 51.

The spelling of 121563479391 in words is "one hundred twenty-one billion, five hundred sixty-three million, four hundred seventy-nine thousand, three hundred ninety-one".