121557145 has 8 divisors (see below), whose sum is σ = 146437704. Its totient is φ = 96866304.

The previous prime is 121557133. The next prime is 121557187. The reversal of 121557145 is 541755121.

It can be written as a sum of positive squares in 4 ways, for example, as 79709184 + 41847961 = 8928^2 + 6469^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121557145 - 2⁷ = 121557017 is a prime.

It is a super-2 number, since 2×121557145² = 29552279001102050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46014 + ... + 48583.

It is an arithmetic number, because the mean of its divisors is an integer number (18304713).

Almost surely, 2^121557145 is an apocalyptic number.

It is an amenable number.

121557145 is a deficient number, since it is larger than the sum of its proper divisors (24880559).

121557145 is an equidigital number, since it uses as much as digits as its factorization.

121557145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94859.

The product of its digits is 7000, while the sum is 31.

The square root of 121557145 is about 11025.2956876448. The cubic root of 121557145 is about 495.3667248068.

The spelling of 121557145 in words is "one hundred twenty-one million, five hundred fifty-seven thousand, one hundred forty-five".