121720254131 has 12 divisors (see below), whose sum is σ = 142994864880. Its totient is φ = 103298655600.

The previous prime is 121720254121. The next prime is 121720254143. The reversal of 121720254131 is 131452027121.

It is not a de Polignac number, because 121720254131 - 2⁶ = 121720254067 is a prime.

It is a super-2 number, since 2×121720254131² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121720254094 and 121720254103.

It is not an unprimeable number, because it can be changed into a prime (121720254121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12292511 + ... + 12302408.

It is an arithmetic number, because the mean of its divisors is an integer number (11916238740).

Almost surely, 2^121720254131 is an apocalyptic number.

121720254131 is a deficient number, since it is larger than the sum of its proper divisors (21274610749).

121720254131 is a wasteful number, since it uses less digits than its factorization.

121720254131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24595034 (or 24595027 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The spelling of 121720254131 in words is "one hundred twenty-one billion, seven hundred twenty million, two hundred fifty-four thousand, one hundred thirty-one".