1672557521 has 2 divisors, whose sum is σ = 1672557522. Its totient is φ = 1672557520.

The previous prime is 1672557511. The next prime is 1672557527. The reversal of 1672557521 is 1257552761.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1222481296 + 450076225 = 34964^2 + 21215^2 .

It is a cyclic number.

It is not a de Polignac number, because 1672557521 - 2¹⁰ = 1672556497 is a prime.

It is a super-2 number, since 2×1672557521² = 5594897322107330882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1672557527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 836278760 + 836278761.

It is an arithmetic number, because the mean of its divisors is an integer number (836278761).

Almost surely, 2^1672557521 is an apocalyptic number.

It is an amenable number.

1672557521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1672557521 is an equidigital number, since it uses as much as digits as its factorization.

1672557521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 147000, while the sum is 41.

The square root of 1672557521 is about 40896.9133431852. The cubic root of 1672557521 is about 1187.0263349845.

The spelling of 1672557521 in words is "one billion, six hundred seventy-two million, five hundred fifty-seven thousand, five hundred twenty-one".