121216021564 has 24 divisors (see below), whose sum is σ = 238877323776. Its totient is φ = 53320830000.

The previous prime is 121216021547. The next prime is 121216021613. The reversal of 121216021564 is 465120612121.

It is a happy number.

It is a super-2 number, since 2×121216021564² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44432662 + ... + 44435389.

It is an arithmetic number, because the mean of its divisors is an integer number (9953221824).

Almost surely, 2^121216021564 is an apocalyptic number.

It is an amenable number.

121216021564 is a deficient number, since it is larger than the sum of its proper divisors (117661302212).

121216021564 is a wasteful number, since it uses less digits than its factorization.

121216021564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88868097 (or 88868095 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 121216021564 its reverse (465120612121), we get a palindrome (586336633685).

The spelling of 121216021564 in words is "one hundred twenty-one billion, two hundred sixteen million, twenty-one thousand, five hundred sixty-four".