721401420 has 24 divisors (see below), whose sum is σ = 2019924144. Its totient is φ = 192373696.

The previous prime is 721401413. The next prime is 721401427. The reversal of 721401420 is 24104127.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (721401413) and next prime (721401427).

It is not an unprimeable number, because it can be changed into a prime (721401427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6011619 + ... + 6011738.

It is an arithmetic number, because the mean of its divisors is an integer number (84163506).

Almost surely, 2^721401420 is an apocalyptic number.

It is an amenable number.

721401420 is an abundant number, since it is smaller than the sum of its proper divisors (1298522724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721401420 is a wasteful number, since it uses less digits than its factorization.

721401420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12023369 (or 12023367 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 721401420 is about 26858.9169550822. The cubic root of 721401420 is about 896.8620844899.

Adding to 721401420 its reverse (24104127), we get a palindrome (745505547).

The spelling of 721401420 in words is "seven hundred twenty-one million, four hundred one thousand, four hundred twenty".