1251020020531 has 2 divisors, whose sum is σ = 1251020020532. Its totient is φ = 1251020020530.

The previous prime is 1251020020493. The next prime is 1251020020573. The reversal of 1251020020531 is 1350200201521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1251020020531 - 2⁷ = 1251020020403 is a prime.

It is a super-5 number, since 5×1251020020531⁵ (a number of 62 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1251020023531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625510010265 + 625510010266.

It is an arithmetic number, because the mean of its divisors is an integer number (625510010266).

Almost surely, 2^{1251020020531} is an apocalyptic number.

1251020020531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251020020531 is an equidigital number, since it uses as much as digits as its factorization.

1251020020531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 22.

The spelling of 1251020020531 in words is "one trillion, two hundred fifty-one billion, twenty million, twenty thousand, five hundred thirty-one".