72121111450 has 24 divisors (see below), whose sum is σ = 137264928768. Its totient is φ = 28177549680.

The previous prime is 72121111427. The next prime is 72121111471. The reversal of 72121111450 is 5411112127.

It is a happy number.

It is a super-2 number, since 2×72121111450² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16770202 + ... + 16774501.

It is an arithmetic number, because the mean of its divisors is an integer number (5719372032).

Almost surely, 2^72121111450 is an apocalyptic number.

72121111450 is a deficient number, since it is larger than the sum of its proper divisors (65143817318).

72121111450 is a wasteful number, since it uses less digits than its factorization.

72121111450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33544758 (or 33544753 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 25.

Adding to 72121111450 its reverse (5411112127), we get a palindrome (77532223577).

The spelling of 72121111450 in words is "seventy-two billion, one hundred twenty-one million, one hundred eleven thousand, four hundred fifty".