1720121953851 has 64 divisors (see below), whose sum is σ = 3039316899840. Its totient is φ = 940093102080.

The previous prime is 1720121953819. The next prime is 1720121953859. The reversal of 1720121953851 is 1583591210271.

1720121953851 is a `hidden beast` number, since 1 + 72 + 0 + 12 + 195 + 385 + 1 = 666.

It is not a de Polignac number, because 1720121953851 - 2⁵ = 1720121953819 is a prime.

It is a super-2 number, since 2×1720121953851² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1720121953797 and 1720121953806.

It is not an unprimeable number, because it can be changed into a prime (1720121953859) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 66552691 + ... + 66578531.

It is an arithmetic number, because the mean of its divisors is an integer number (47489326560).

Almost surely, 2^{1720121953851} is an apocalyptic number.

1720121953851 is a deficient number, since it is larger than the sum of its proper divisors (1319194945989).

1720121953851 is a wasteful number, since it uses less digits than its factorization.

1720121953851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41193 (or 41187 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 45.

The spelling of 1720121953851 in words is "one trillion, seven hundred twenty billion, one hundred twenty-one million, nine hundred fifty-three thousand, eight hundred fifty-one".