121406557 has 4 divisors (see below), whose sum is σ = 125593020. Its totient is φ = 117220096.

The previous prime is 121406533. The next prime is 121406563. The reversal of 121406557 is 755604121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 755604121 = 37 ⋅20421733.

It can be written as a sum of positive squares in 2 ways, for example, as 35176761 + 86229796 = 5931^2 + 9286^2 .

It is a cyclic number.

It is not a de Polignac number, because 121406557 - 2⁷ = 121406429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121406357) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2093188 + ... + 2093245.

It is an arithmetic number, because the mean of its divisors is an integer number (31398255).

Almost surely, 2^121406557 is an apocalyptic number.

It is an amenable number.

121406557 is a deficient number, since it is larger than the sum of its proper divisors (4186463).

121406557 is an equidigital number, since it uses as much as digits as its factorization.

121406557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4186462.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 121406557 is about 11018.4643666892. The cubic root of 121406557 is about 495.1620827583.

The spelling of 121406557 in words is "one hundred twenty-one million, four hundred six thousand, five hundred fifty-seven".