121421391 has 16 divisors (see below), whose sum is σ = 199256064. Its totient is φ = 64046304.

The previous prime is 121421369. The next prime is 121421413. The reversal of 121421391 is 193124121.

It is an interprime number because it is at equal distance from previous prime (121421369) and next prime (121421413).

It is not a de Polignac number, because 121421391 - 2¹⁰ = 121420367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121421491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222111 + ... + 222656.

It is an arithmetic number, because the mean of its divisors is an integer number (12453504).

Almost surely, 2^121421391 is an apocalyptic number.

121421391 is a deficient number, since it is larger than the sum of its proper divisors (77834673).

121421391 is a wasteful number, since it uses less digits than its factorization.

121421391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444790.

The product of its digits is 432, while the sum is 24.

The square root of 121421391 is about 11019.1374889326. The cubic root of 121421391 is about 495.1822489816.

The spelling of 121421391 in words is "one hundred twenty-one million, four hundred twenty-one thousand, three hundred ninety-one".