621071557 has 8 divisors (see below), whose sum is σ = 661409496. Its totient is φ = 581156352.

The previous prime is 621071551. The next prime is 621071573. The reversal of 621071557 is 755170126.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 243391201 + 377680356 = 15601^2 + 19434^2 .

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-621071557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621071551) 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, 102648 + ... + 108529.

It is an arithmetic number, because the mean of its divisors is an integer number (82676187).

Almost surely, 2^621071557 is an apocalyptic number.

It is an amenable number.

621071557 is a deficient number, since it is larger than the sum of its proper divisors (40337939).

621071557 is a wasteful number, since it uses less digits than its factorization.

621071557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211367.

The product of its (nonzero) digits is 14700, while the sum is 34.

The square root of 621071557 is about 24921.3072891452. The cubic root of 621071557 is about 853.1928621960.

The spelling of 621071557 in words is "six hundred twenty-one million, seventy-one thousand, five hundred fifty-seven".