721020151 has 4 divisors (see below), whose sum is σ = 758968600. Its totient is φ = 683071704.

The previous prime is 721020107. The next prime is 721020163. The reversal of 721020151 is 151020127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 151020127 = 31 ⋅4871617.

It is a cyclic number.

It is not a de Polignac number, because 721020151 - 2¹⁹ = 720495863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 37948429 = 721020151 / (7 + 2 + 1 + 0 + 2 + 0 + 1 + 5 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721020101) 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, 18974196 + ... + 18974233.

It is an arithmetic number, because the mean of its divisors is an integer number (189742150).

Almost surely, 2^721020151 is an apocalyptic number.

721020151 is a deficient number, since it is larger than the sum of its proper divisors (37948449).

721020151 is a wasteful number, since it uses less digits than its factorization.

721020151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37948448.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 721020151 is about 26851.8183928016. The cubic root of 721020151 is about 896.7040559827.

Adding to 721020151 its reverse (151020127), we get a palindrome (872040278).

The spelling of 721020151 in words is "seven hundred twenty-one million, twenty thousand, one hundred fifty-one".