15649897 has 2 divisors, whose sum is σ = 15649898. Its totient is φ = 15649896.

The previous prime is 15649889. The next prime is 15649951. The reversal of 15649897 is 79894651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15452761 + 197136 = 3931^2 + 444^2 .

It is a cyclic number.

It is not a de Polignac number, because 15649897 - 2³ = 15649889 is a prime.

It is a super-3 number, since 3×15649897³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 15649897.

It is not a weakly prime, because it can be changed into another prime (15649847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7824948 + 7824949.

It is an arithmetic number, because the mean of its divisors is an integer number (7824949).

Almost surely, 2^15649897 is an apocalyptic number.

It is an amenable number.

15649897 is a deficient number, since it is larger than the sum of its proper divisors (1).

15649897 is an equidigital number, since it uses as much as digits as its factorization.

15649897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 49.

The square root of 15649897 is about 3955.9950707755. The cubic root of 15649897 is about 250.1327135360.

The spelling of 15649897 in words is "fifteen million, six hundred forty-nine thousand, eight hundred ninety-seven".