661498153 has 2 divisors, whose sum is σ = 661498154. Its totient is φ = 661498152.

The previous prime is 661498151. The next prime is 661498171. The reversal of 661498153 is 351894166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 599907049 + 61591104 = 24493^2 + 7848^2 .

It is a cyclic number.

It is not a de Polignac number, because 661498153 - 2¹ = 661498151 is a prime.

It is a super-2 number, since 2×661498153² = 875159612844822818, which contains 22 as substring.

Together with 661498151, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (661498151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330749076 + 330749077.

It is an arithmetic number, because the mean of its divisors is an integer number (330749077).

Almost surely, 2^661498153 is an apocalyptic number.

It is an amenable number.

661498153 is a deficient number, since it is larger than the sum of its proper divisors (1).

661498153 is an equidigital number, since it uses as much as digits as its factorization.

661498153 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 43.

The square root of 661498153 is about 25719.6063927891. The cubic root of 661498153 is about 871.3170490869.

The spelling of 661498153 in words is "six hundred sixty-one million, four hundred ninety-eight thousand, one hundred fifty-three".