121530531406 has 4 divisors (see below), whose sum is σ = 182295797112. Its totient is φ = 60765265702.

The previous prime is 121530531401. The next prime is 121530531439. The reversal of 121530531406 is 604135035121.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121530531401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30382632850 + ... + 30382632853.

It is an arithmetic number, because the mean of its divisors is an integer number (45573949278).

Almost surely, 2^121530531406 is an apocalyptic number.

121530531406 is a deficient number, since it is larger than the sum of its proper divisors (60765265706).

121530531406 is an equidigital number, since it uses as much as digits as its factorization.

121530531406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60765265705.

The product of its (nonzero) digits is 10800, while the sum is 31.

Adding to 121530531406 its reverse (604135035121), we get a palindrome (725665566527).

The spelling of 121530531406 in words is "one hundred twenty-one billion, five hundred thirty million, five hundred thirty-one thousand, four hundred six".