56721701 has 8 divisors (see below), whose sum is σ = 57459864. Its totient is φ = 55987200.

The previous prime is 56721677. The next prime is 56721757. The reversal of 56721701 is 10712765.

It can be written as a sum of positive squares in 4 ways, for example, as 30813601 + 25908100 = 5551^2 + 5090^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56721701 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56721781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43085 + ... + 44381.

It is an arithmetic number, because the mean of its divisors is an integer number (7182483).

Almost surely, 2^56721701 is an apocalyptic number.

It is an amenable number.

56721701 is a deficient number, since it is larger than the sum of its proper divisors (738163).

56721701 is a wasteful number, since it uses less digits than its factorization.

56721701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1831.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 56721701 is about 7531.3810818468. The cubic root of 56721701 is about 384.2227553231. Note that the first 3 decimals are identical.

The spelling of 56721701 in words is "fifty-six million, seven hundred twenty-one thousand, seven hundred one".