721157020 has 48 divisors (see below), whose sum is σ = 1536444000. Its totient is φ = 284302080.

The previous prime is 721157009. The next prime is 721157023. The reversal of 721157020 is 20751127.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721157023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413350 + ... + 415090.

It is an arithmetic number, because the mean of its divisors is an integer number (32009250).

Almost surely, 2^721157020 is an apocalyptic number.

It is an amenable number.

721157020 is an abundant number, since it is smaller than the sum of its proper divisors (815286980).

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

721157020 is a wasteful number, since it uses less digits than its factorization.

721157020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2038 (or 2036 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 721157020 is about 26854.3668702131. The cubic root of 721157020 is about 896.7607919015.

The spelling of 721157020 in words is "seven hundred twenty-one million, one hundred fifty-seven thousand, twenty".