620507721 has 8 divisors (see below), whose sum is σ = 828755424. Its totient is φ = 412965920.

The previous prime is 620507717. The next prime is 620507737. The reversal of 620507721 is 127705026.

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

It is a cyclic number.

It is not a de Polignac number, because 620507721 - 2² = 620507717 is a prime.

It is a super-2 number, since 2×620507721² = 770059663641227682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (620507711) 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, 174420 + ... + 177941.

It is an arithmetic number, because the mean of its divisors is an integer number (103594428).

Almost surely, 2^620507721 is an apocalyptic number.

It is an amenable number.

620507721 is a deficient number, since it is larger than the sum of its proper divisors (208247703).

620507721 is a wasteful number, since it uses less digits than its factorization.

620507721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352951.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 620507721 is about 24909.9923926122. The cubic root of 620507721 is about 852.9345953910.

The spelling of 620507721 in words is "six hundred twenty million, five hundred seven thousand, seven hundred twenty-one".