100720651 has 4 divisors (see below), whose sum is σ = 101445400. Its totient is φ = 99995904.

The previous prime is 100720649. The next prime is 100720661. The reversal of 100720651 is 156027001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 156027001 = 13 ⋅12002077.

It is a cyclic number.

It is not a de Polignac number, because 100720651 - 2¹ = 100720649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100720661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362166 + ... + 362443.

It is an arithmetic number, because the mean of its divisors is an integer number (25361350).

Almost surely, 2^100720651 is an apocalyptic number.

100720651 is a deficient number, since it is larger than the sum of its proper divisors (724749).

100720651 is an equidigital number, since it uses as much as digits as its factorization.

100720651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724748.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 100720651 is about 10035.9678656321. The cubic root of 100720651 is about 465.2712041861.

Adding to 100720651 its reverse (156027001), we get a palindrome (256747652).

The spelling of 100720651 in words is "one hundred million, seven hundred twenty thousand, six hundred fifty-one".